Combine several sources into one fair answer
Grade 11 Reading Worksheet - Challenge Me
Circle the best answer.
Read this first
Four Source Notes on Night Lights and Migrating Birds (research notes: four sources on one question)
Research question: Do dimmer or shielded outdoor lights help migrating birds stay on course at night?
Source A: study by Dr. Helena Marsh-Okafor, a bird scientist at the Hesketh Bird Observatory, 2024; primary, measured counts. [1] On spring and fall nights, Marsh-Okafor's team used night cameras to count the birds circling twelve brightly lit office towers in Hesketh. [2] On nights when the towers dimmed most of their outdoor and upper-floor lights, about 60 percent fewer birds circled them. [3] The drop was largest on cloudy and foggy nights, when migrating birds fly lower and lights draw them most strongly. [4] On clear, windy nights the difference was small, because fewer birds flew low enough to be pulled toward the towers.
Source B: study by Dr. Pavel Ilunga, an engineer at the Rookhaven Technical Institute, 2025; primary, weather radar. [5] Ilunga used radar to track birds crossing two small towns, one of which had switched to shielded streetlights that point downward. [6] He found no clear difference in how many birds changed course over the two towns during one fall season. [7] He notes that streetlights are far dimmer and lower than lit towers, so his result may not apply to cities. [8] He recommends testing shielded lamps over several seasons before anyone draws a firm conclusion.
Source C: report by the Tilbury Point Night Sky Volunteers, 2025; primary, volunteer counts. [9] For two migration seasons, volunteers walked around six downtown buildings at dawn and recorded the tired birds resting on sidewalks and ledges. [10] After four of the buildings agreed to dim their lights at night, volunteers found about half as many tired birds near those four. [11] The volunteers searched only on weekdays, and their counts depended on how many helpers came out.
Source D: web page of Glimmerfield Signs, a company that sells lighted building signs, 2026; no study given. [12] The page argues that dimming building lights does nothing for birds, because birds steer by the stars and the earth's magnetic field. [13] It warns that dark buildings look closed and dim streets feel unwelcoming to evening shoppers. [14] The page cites no study or count and ends with a discount offer on new lighted signs.
Draft so far: Dimming building lights appears to help migrating birds. Marsh-Okafor's team counted about 60 percent fewer birds circling dimmed towers, and volunteers found about half as many tired birds near dimmed buildings (Marsh-Okafor; Tilbury Point Night Sky Volunteers).
Ari must add Source B to this draft without bending it. Which sentence places B's finding fairly?
- Ilunga's radar study of a town with shielded streetlights adds further support, since the birds over that town changed course less often.
- Ilunga's radar found no clear change over a town with shielded streetlights, but those lamps are dimmer and lower than towers, so it may not apply to cities.
- Ilunga's radar found no clear change over the shielded town, so the research is evenly split and no one can yet say whether dimming lights helps.
- Ilunga's radar found no clear change over the shielded town, but the study can be set aside, because radar is not a serious tool for counting small birds at night.
Four Source Notes on Night Lights and Migrating Birds (research notes: four sources on one question)
Research question: Do dimmer or shielded outdoor lights help migrating birds stay on course at night?
Source A: study by Dr. Helena Marsh-Okafor, a bird scientist at the Hesketh Bird Observatory, 2024; primary, measured counts. [1] On spring and fall nights, Marsh-Okafor's team used night cameras to count the birds circling twelve brightly lit office towers in Hesketh. [2] On nights when the towers dimmed most of their outdoor and upper-floor lights, about 60 percent fewer birds circled them. [3] The drop was largest on cloudy and foggy nights, when migrating birds fly lower and lights draw them most strongly. [4] On clear, windy nights the difference was small, because fewer birds flew low enough to be pulled toward the towers.
Source B: study by Dr. Pavel Ilunga, an engineer at the Rookhaven Technical Institute, 2025; primary, weather radar. [5] Ilunga used radar to track birds crossing two small towns, one of which had switched to shielded streetlights that point downward. [6] He found no clear difference in how many birds changed course over the two towns during one fall season. [7] He notes that streetlights are far dimmer and lower than lit towers, so his result may not apply to cities. [8] He recommends testing shielded lamps over several seasons before anyone draws a firm conclusion.
Source C: report by the Tilbury Point Night Sky Volunteers, 2025; primary, volunteer counts. [9] For two migration seasons, volunteers walked around six downtown buildings at dawn and recorded the tired birds resting on sidewalks and ledges. [10] After four of the buildings agreed to dim their lights at night, volunteers found about half as many tired birds near those four. [11] The volunteers searched only on weekdays, and their counts depended on how many helpers came out.
Source D: web page of Glimmerfield Signs, a company that sells lighted building signs, 2026; no study given. [12] The page argues that dimming building lights does nothing for birds, because birds steer by the stars and the earth's magnetic field. [13] It warns that dark buildings look closed and dim streets feel unwelcoming to evening shoppers. [14] The page cites no study or count and ends with a discount offer on new lighted signs.
Draft sentence: Both a tower study and a radar study show that dimming lights helps migrating birds (Marsh-Okafor; Ilunga).
This draft sentence has one flaw. Which revision fixes it, as Esme checks it against the cards?
- A tower study and a radar study both show that dimming outdoor lights helps the birds that migrate at night (Marsh-Okafor; Ilunga).
- A tower count and a sign company's page both show that dimming lights helps migrating birds (Marsh-Okafor; Glimmerfield Signs).
- A tower count and a volunteer count both found fewer birds drawn in when buildings dimmed their lights (Marsh-Okafor; Tilbury Point Night Sky Volunteers).
- A tower count, a radar study and a volunteer count agree that dimming lights keeps migrating birds safe (Marsh-Okafor; Ilunga; Tilbury Point Night Sky Volunteers).
Four Source Notes on Night Lights and Migrating Birds (research notes: four sources on one question)
Research question: Do dimmer or shielded outdoor lights help migrating birds stay on course at night?
Source A: study by Dr. Helena Marsh-Okafor, a bird scientist at the Hesketh Bird Observatory, 2024; primary, measured counts. [1] On spring and fall nights, Marsh-Okafor's team used night cameras to count the birds circling twelve brightly lit office towers in Hesketh. [2] On nights when the towers dimmed most of their outdoor and upper-floor lights, about 60 percent fewer birds circled them. [3] The drop was largest on cloudy and foggy nights, when migrating birds fly lower and lights draw them most strongly. [4] On clear, windy nights the difference was small, because fewer birds flew low enough to be pulled toward the towers.
Source B: study by Dr. Pavel Ilunga, an engineer at the Rookhaven Technical Institute, 2025; primary, weather radar. [5] Ilunga used radar to track birds crossing two small towns, one of which had switched to shielded streetlights that point downward. [6] He found no clear difference in how many birds changed course over the two towns during one fall season. [7] He notes that streetlights are far dimmer and lower than lit towers, so his result may not apply to cities. [8] He recommends testing shielded lamps over several seasons before anyone draws a firm conclusion.
Source C: report by the Tilbury Point Night Sky Volunteers, 2025; primary, volunteer counts. [9] For two migration seasons, volunteers walked around six downtown buildings at dawn and recorded the tired birds resting on sidewalks and ledges. [10] After four of the buildings agreed to dim their lights at night, volunteers found about half as many tired birds near those four. [11] The volunteers searched only on weekdays, and their counts depended on how many helpers came out.
Source D: web page of Glimmerfield Signs, a company that sells lighted building signs, 2026; no study given. [12] The page argues that dimming building lights does nothing for birds, because birds steer by the stars and the earth's magnetic field. [13] It warns that dark buildings look closed and dim streets feel unwelcoming to evening shoppers. [14] The page cites no study or count and ends with a discount offer on new lighted signs.
Draft so far: Dimming tall buildings' lights seems to help migrating birds: two counts found far fewer birds drawn in, though a radar study of dim streetlights found no clear change (Marsh-Okafor; Tilbury Point Night Sky Volunteers; Ilunga).
Jun must add Source D's claim to the draft fairly. Which sentence places it?
- A sign company's web page says dimming does nothing for birds, which weighs as much as the two measured counts and leaves the question open.
- A sign company's web page says dimming does nothing for birds, but the page is plainly wrong and not worth a reader's time.
- A sign company's web page says dimming does nothing because birds steer by the stars, but it cites no study and sells lighted signs.
- A sign company's web page agrees that birds steer by the stars, which helps explain why dimmed buildings draw fewer birds.
Four Source Notes on Night Lights and Migrating Birds (research notes: four sources on one question)
Research question: Do dimmer or shielded outdoor lights help migrating birds stay on course at night?
Source A: study by Dr. Helena Marsh-Okafor, a bird scientist at the Hesketh Bird Observatory, 2024; primary, measured counts. [1] On spring and fall nights, Marsh-Okafor's team used night cameras to count the birds circling twelve brightly lit office towers in Hesketh. [2] On nights when the towers dimmed most of their outdoor and upper-floor lights, about 60 percent fewer birds circled them. [3] The drop was largest on cloudy and foggy nights, when migrating birds fly lower and lights draw them most strongly. [4] On clear, windy nights the difference was small, because fewer birds flew low enough to be pulled toward the towers.
Source B: study by Dr. Pavel Ilunga, an engineer at the Rookhaven Technical Institute, 2025; primary, weather radar. [5] Ilunga used radar to track birds crossing two small towns, one of which had switched to shielded streetlights that point downward. [6] He found no clear difference in how many birds changed course over the two towns during one fall season. [7] He notes that streetlights are far dimmer and lower than lit towers, so his result may not apply to cities. [8] He recommends testing shielded lamps over several seasons before anyone draws a firm conclusion.
Source C: report by the Tilbury Point Night Sky Volunteers, 2025; primary, volunteer counts. [9] For two migration seasons, volunteers walked around six downtown buildings at dawn and recorded the tired birds resting on sidewalks and ledges. [10] After four of the buildings agreed to dim their lights at night, volunteers found about half as many tired birds near those four. [11] The volunteers searched only on weekdays, and their counts depended on how many helpers came out.
Source D: web page of Glimmerfield Signs, a company that sells lighted building signs, 2026; no study given. [12] The page argues that dimming building lights does nothing for birds, because birds steer by the stars and the earth's magnetic field. [13] It warns that dark buildings look closed and dim streets feel unwelcoming to evening shoppers. [14] The page cites no study or count and ends with a discount offer on new lighted signs.
A small town has streetlights but no tall buildings. Which answer do the cards allow for that town, as Kira reads them?
- Shielding the town's streetlights should cut the birds drawn off course by about 60 percent, as dimming did at the towers.
- The town need not bother, because the sign company's page explains that birds steer by the stars instead of by lights.
- The cards tell us nothing about outdoor lights and migrating birds, so the town has no evidence of any kind to weigh.
- The cards cannot yet say, since the one streetlight study found no clear change in a single season and the tower results may not apply.
Four Source Notes on Night Lights and Migrating Birds (research notes: four sources on one question)
Research question: Do dimmer or shielded outdoor lights help migrating birds stay on course at night?
Source A: study by Dr. Helena Marsh-Okafor, a bird scientist at the Hesketh Bird Observatory, 2024; primary, measured counts. [1] On spring and fall nights, Marsh-Okafor's team used night cameras to count the birds circling twelve brightly lit office towers in Hesketh. [2] On nights when the towers dimmed most of their outdoor and upper-floor lights, about 60 percent fewer birds circled them. [3] The drop was largest on cloudy and foggy nights, when migrating birds fly lower and lights draw them most strongly. [4] On clear, windy nights the difference was small, because fewer birds flew low enough to be pulled toward the towers.
Source B: study by Dr. Pavel Ilunga, an engineer at the Rookhaven Technical Institute, 2025; primary, weather radar. [5] Ilunga used radar to track birds crossing two small towns, one of which had switched to shielded streetlights that point downward. [6] He found no clear difference in how many birds changed course over the two towns during one fall season. [7] He notes that streetlights are far dimmer and lower than lit towers, so his result may not apply to cities. [8] He recommends testing shielded lamps over several seasons before anyone draws a firm conclusion.
Source C: report by the Tilbury Point Night Sky Volunteers, 2025; primary, volunteer counts. [9] For two migration seasons, volunteers walked around six downtown buildings at dawn and recorded the tired birds resting on sidewalks and ledges. [10] After four of the buildings agreed to dim their lights at night, volunteers found about half as many tired birds near those four. [11] The volunteers searched only on weekdays, and their counts depended on how many helpers came out.
Source D: web page of Glimmerfield Signs, a company that sells lighted building signs, 2026; no study given. [12] The page argues that dimming building lights does nothing for birds, because birds steer by the stars and the earth's magnetic field. [13] It warns that dark buildings look closed and dim streets feel unwelcoming to evening shoppers. [14] The page cites no study or count and ends with a discount offer on new lighted signs.
Draft sentence: Dimming lights helps migrating birds, cutting the birds circling towers by about 60 percent and halving the tired birds found at dawn (Marsh-Okafor; Tilbury Point Night Sky Volunteers).
Luz finds one flaw in this draft sentence. Which revision fixes that flaw?
- Dimming tall buildings' lights cut the birds drawn to them in two counts, though a radar study of shielded streetlights found no clear change (Marsh-Okafor; Tilbury Point Night Sky Volunteers; Ilunga).
- Dimming lights helps migrating birds, cutting circling at towers by about 60 percent and halving tired birds at dawn, in two careful counts (Marsh-Okafor; Tilbury Point Night Sky Volunteers).
- Dimming lights of any size helps migrating birds, as two counts and a radar study agree (Marsh-Okafor; Tilbury Point Night Sky Volunteers; Ilunga).
- Dimming lights helps migrating birds, as two counts show and as even a sign company's own page admits that birds steer by the stars (Marsh-Okafor; Tilbury Point Night Sky Volunteers; Glimmerfield Signs).
Four Source Notes on Standing Desks (research notes: four sources on one question)
Research question: Do standing desks help high school students pay attention in class?
Source A: study by Dr. Lorraine Achterberg, a researcher at the Velmont Center for Learning Research, 2024; primary, measured. [1] Achterberg's team gave standing desks to six ninth-grade classrooms for a school year and compared them with six similar classrooms that kept ordinary desks. [2] Trained observers who visited each room every two weeks recorded about 12 percent more time on task in the rooms with standing desks. [3] Students in those rooms also scored slightly higher on short tests of attention given in the fall and again in the spring. [4] The gains were largest in the first two months and grew smaller as the school year went on.
Source B: study by Dr. Kofi Brandvold, a physical therapist at the Ashby Falls Medical College, 2025; primary, measured. [5] Brandvold measured how much students moved during the school day and found that students with standing desks sat less and moved more. [6] Students with standing desks also reported less stiffness in their backs and legs by the end of the term. [7] He found no difference in their grades or in their teachers' ratings of attention after one semester. [8] He notes that most students had gone back to sitting on tall stools at their standing desks after the first few weeks.
Source C: survey of 210 teachers by the Corriden Teachers' Association, 2025; primary, teachers' opinions. [9] About 70 percent of the teachers who had used standing desks said that their students seemed more alert in class. [10] Some teachers said that the desks were noisy to move and took up more of the room than ordinary desks. [11] The association, which had asked the district to buy the desks, did not test or observe any students itself.
Source D: column by health writer Bettina Ruiz-Fairweather in the Rookhaven Ledger, 2026; secondary, based on one classroom visit. [12] After visiting one classroom, Ruiz-Fairweather writes that standing desks "transform" students into eager learners. [13] She quotes one teacher who says that restless students no longer drift off during long lessons. [14] The column does not mention any study or say how many students the teacher was describing.
Which one-sentence answer to the research question do the four cards allow, as Noah drafts it?
- Standing desks make high school students more attentive, as a year-long study, a survey of teachers and a news column agree.
- Because the studies disagree, the four cards say nothing yet about standing desks and how students pay attention.
- Standing desks raise students' time on task by about 12 percent, and the gain holds for the whole school year.
- Standing desks may raise attention a little at first, but the gain fades, and one study found no change after a semester.
Four Source Notes on Standing Desks (research notes: four sources on one question)
Research question: Do standing desks help high school students pay attention in class?
Source A: study by Dr. Lorraine Achterberg, a researcher at the Velmont Center for Learning Research, 2024; primary, measured. [1] Achterberg's team gave standing desks to six ninth-grade classrooms for a school year and compared them with six similar classrooms that kept ordinary desks. [2] Trained observers who visited each room every two weeks recorded about 12 percent more time on task in the rooms with standing desks. [3] Students in those rooms also scored slightly higher on short tests of attention given in the fall and again in the spring. [4] The gains were largest in the first two months and grew smaller as the school year went on.
Source B: study by Dr. Kofi Brandvold, a physical therapist at the Ashby Falls Medical College, 2025; primary, measured. [5] Brandvold measured how much students moved during the school day and found that students with standing desks sat less and moved more. [6] Students with standing desks also reported less stiffness in their backs and legs by the end of the term. [7] He found no difference in their grades or in their teachers' ratings of attention after one semester. [8] He notes that most students had gone back to sitting on tall stools at their standing desks after the first few weeks.
Source C: survey of 210 teachers by the Corriden Teachers' Association, 2025; primary, teachers' opinions. [9] About 70 percent of the teachers who had used standing desks said that their students seemed more alert in class. [10] Some teachers said that the desks were noisy to move and took up more of the room than ordinary desks. [11] The association, which had asked the district to buy the desks, did not test or observe any students itself.
Source D: column by health writer Bettina Ruiz-Fairweather in the Rookhaven Ledger, 2026; secondary, based on one classroom visit. [12] After visiting one classroom, Ruiz-Fairweather writes that standing desks "transform" students into eager learners. [13] She quotes one teacher who says that restless students no longer drift off during long lessons. [14] The column does not mention any study or say how many students the teacher was describing.
Draft sentence: Standing desks help students focus, since about 70 percent of teachers who used them said their students seemed more alert (Corriden Teachers' Association).
Pia spots one flaw in this draft sentence. Which revision fixes it?
- Standing desks may help a little: observers recorded about 12 percent more time on task, and most teachers surveyed said students seemed more alert (Achterberg; Corriden Teachers' Association).
- Standing desks help students focus, since about 70 percent of the surveyed teachers who used the desks said their classes seemed more alert (Corriden Teachers' Association).
- Standing desks help students focus, as a year-long study and a survey of 210 teachers both show beyond doubt (Achterberg; Corriden Teachers' Association).
- Standing desks help students focus, as Brandvold's study and the teachers' survey both found (Brandvold; Corriden Teachers' Association).
Four Source Notes on Standing Desks (research notes: four sources on one question)
Research question: Do standing desks help high school students pay attention in class?
Source A: study by Dr. Lorraine Achterberg, a researcher at the Velmont Center for Learning Research, 2024; primary, measured. [1] Achterberg's team gave standing desks to six ninth-grade classrooms for a school year and compared them with six similar classrooms that kept ordinary desks. [2] Trained observers who visited each room every two weeks recorded about 12 percent more time on task in the rooms with standing desks. [3] Students in those rooms also scored slightly higher on short tests of attention given in the fall and again in the spring. [4] The gains were largest in the first two months and grew smaller as the school year went on.
Source B: study by Dr. Kofi Brandvold, a physical therapist at the Ashby Falls Medical College, 2025; primary, measured. [5] Brandvold measured how much students moved during the school day and found that students with standing desks sat less and moved more. [6] Students with standing desks also reported less stiffness in their backs and legs by the end of the term. [7] He found no difference in their grades or in their teachers' ratings of attention after one semester. [8] He notes that most students had gone back to sitting on tall stools at their standing desks after the first few weeks.
Source C: survey of 210 teachers by the Corriden Teachers' Association, 2025; primary, teachers' opinions. [9] About 70 percent of the teachers who had used standing desks said that their students seemed more alert in class. [10] Some teachers said that the desks were noisy to move and took up more of the room than ordinary desks. [11] The association, which had asked the district to buy the desks, did not test or observe any students itself.
Source D: column by health writer Bettina Ruiz-Fairweather in the Rookhaven Ledger, 2026; secondary, based on one classroom visit. [12] After visiting one classroom, Ruiz-Fairweather writes that standing desks "transform" students into eager learners. [13] She quotes one teacher who says that restless students no longer drift off during long lessons. [14] The column does not mention any study or say how many students the teacher was describing.
Draft so far: Standing desks may help a little: observers recorded about 12 percent more time on task, though the gain faded, and another study found no change after a semester (Achterberg; Brandvold).
Ren wants to add Source D's column to the draft fairly. Which sentence places it?
- A newspaper column says the desks "transform" students, but it rests on one classroom visit and a teacher's impression, not a study.
- A newspaper column agrees that the gains are modest and fade with time, based on a visit to one classroom.
- A newspaper column says the desks "transform" students, but a columnist's opinions do not belong in a research paper.
- A newspaper column says the desks "transform" students, which weighs as much as the year-long study and leaves the matter open for now.
Four Source Notes on Standing Desks (research notes: four sources on one question)
Research question: Do standing desks help high school students pay attention in class?
Source A: study by Dr. Lorraine Achterberg, a researcher at the Velmont Center for Learning Research, 2024; primary, measured. [1] Achterberg's team gave standing desks to six ninth-grade classrooms for a school year and compared them with six similar classrooms that kept ordinary desks. [2] Trained observers who visited each room every two weeks recorded about 12 percent more time on task in the rooms with standing desks. [3] Students in those rooms also scored slightly higher on short tests of attention given in the fall and again in the spring. [4] The gains were largest in the first two months and grew smaller as the school year went on.
Source B: study by Dr. Kofi Brandvold, a physical therapist at the Ashby Falls Medical College, 2025; primary, measured. [5] Brandvold measured how much students moved during the school day and found that students with standing desks sat less and moved more. [6] Students with standing desks also reported less stiffness in their backs and legs by the end of the term. [7] He found no difference in their grades or in their teachers' ratings of attention after one semester. [8] He notes that most students had gone back to sitting on tall stools at their standing desks after the first few weeks.
Source C: survey of 210 teachers by the Corriden Teachers' Association, 2025; primary, teachers' opinions. [9] About 70 percent of the teachers who had used standing desks said that their students seemed more alert in class. [10] Some teachers said that the desks were noisy to move and took up more of the room than ordinary desks. [11] The association, which had asked the district to buy the desks, did not test or observe any students itself.
Source D: column by health writer Bettina Ruiz-Fairweather in the Rookhaven Ledger, 2026; secondary, based on one classroom visit. [12] After visiting one classroom, Ruiz-Fairweather writes that standing desks "transform" students into eager learners. [13] She quotes one teacher who says that restless students no longer drift off during long lessons. [14] The column does not mention any study or say how many students the teacher was describing.
Which answer do the cards allow about the desks' effect late in the school year, as Tala reads them?
- Late in the year, students at standing desks pay far more attention, as most of the teachers in the survey reported.
- Late in the year, standing desks still transform students into eager learners, as one classroom shows.
- No source looked past the first few weeks, so the cards say nothing about the desks late in the year.
- The cards suggest a smaller effect late in the year, since A's gains shrank as the year went on and B found none after a semester.
Four Source Notes on Standing Desks (research notes: four sources on one question)
Research question: Do standing desks help high school students pay attention in class?
Source A: study by Dr. Lorraine Achterberg, a researcher at the Velmont Center for Learning Research, 2024; primary, measured. [1] Achterberg's team gave standing desks to six ninth-grade classrooms for a school year and compared them with six similar classrooms that kept ordinary desks. [2] Trained observers who visited each room every two weeks recorded about 12 percent more time on task in the rooms with standing desks. [3] Students in those rooms also scored slightly higher on short tests of attention given in the fall and again in the spring. [4] The gains were largest in the first two months and grew smaller as the school year went on.
Source B: study by Dr. Kofi Brandvold, a physical therapist at the Ashby Falls Medical College, 2025; primary, measured. [5] Brandvold measured how much students moved during the school day and found that students with standing desks sat less and moved more. [6] Students with standing desks also reported less stiffness in their backs and legs by the end of the term. [7] He found no difference in their grades or in their teachers' ratings of attention after one semester. [8] He notes that most students had gone back to sitting on tall stools at their standing desks after the first few weeks.
Source C: survey of 210 teachers by the Corriden Teachers' Association, 2025; primary, teachers' opinions. [9] About 70 percent of the teachers who had used standing desks said that their students seemed more alert in class. [10] Some teachers said that the desks were noisy to move and took up more of the room than ordinary desks. [11] The association, which had asked the district to buy the desks, did not test or observe any students itself.
Source D: column by health writer Bettina Ruiz-Fairweather in the Rookhaven Ledger, 2026; secondary, based on one classroom visit. [12] After visiting one classroom, Ruiz-Fairweather writes that standing desks "transform" students into eager learners. [13] She quotes one teacher who says that restless students no longer drift off during long lessons. [14] The column does not mention any study or say how many students the teacher was describing.
Draft sentence: Two studies found that standing desks raise students' grades (Achterberg; Brandvold).
This draft sentence claims a shared finding. Which revision fixes its one flaw, as Zee checks the cards?
- Two careful studies found that standing desks raise high school students' grades over a school year (Achterberg; Brandvold).
- A study and a teacher survey found that standing desks raise students' grades (Achterberg; Corriden Teachers' Association).
- One study found slightly higher attention scores with standing desks, while another found no change in grades (Achterberg; Brandvold).
- Two studies found that standing desks greatly raise students' attention scores as well as their grades in class (Achterberg; Brandvold).