Summarize an article without bias
Grade 9 Reading Worksheet - Challenge Me
Circle the best answer.
Read this first
The Telescope That Needed Glasses (article)
[1] When the Hubble Space Telescope was carried into orbit by the space shuttle Discovery in April 1990, astronomers expected the sharpest pictures of space ever taken. [2] From above the blurring air, its main mirror, about 2.4 meters across, was meant to show details that no telescope on the ground could see. [3] The mirror had been tested many times before launch, and the tests had said that its shape was nearly perfect.
[4] Within weeks, the first images arrived, and stars that should have appeared as sharp points were surrounded by a fuzzy haze. [5] Engineers traced the problem to the edge of the mirror, which had been ground slightly too flat, by an amount about one-fiftieth the thickness of a sheet of paper. [6] The error had slipped through because a testing instrument used during the grinding had been assembled with one part slightly out of place, so it reported a flawed shape as correct.
[7] The mistake was tiny, but because it was known so exactly, it could be fixed without a new mirror. [8] So engineers designed new optics that bent the light by the same amount the other way, much as glasses fix the focus of an eye. [9] In December 1993, astronauts aboard the space shuttle Endeavour reached the telescope and, over five spacewalks, installed a new camera and a set of small correcting mirrors.
[10] The first pictures after the repair showed stars as crisp points of light, and the haze was gone. [11] In the years that followed, the telescope helped measure how fast the universe is growing and showed galaxies so far away that their light left them billions of years ago. [12] Its early failure is remembered along with its success, because measuring the flaw so exactly was what made the repair possible.
Ari must fit the article into one sentence. Which sentence gives the central idea and how it is refined?
- Because the flaw was measured so precisely, astronauts could install correcting optics in 1993, and the telescope's pictures became sharp.
- In December 1993, astronauts aboard Endeavour made five spacewalks to install a new camera and a set of small correcting mirrors on Hubble.
- Hubble's mirror had a tiny flaw that blurred its first images, but because the flaw was measured precisely, astronauts corrected it in 1993.
- Hubble's mirror reached orbit in 1990 with an embarrassing flaw that blurred its first images, but astronauts heroically corrected it in 1993.
The Telescope That Needed Glasses (article)
[1] When the Hubble Space Telescope was carried into orbit by the space shuttle Discovery in April 1990, astronomers expected the sharpest pictures of space ever taken. [2] From above the blurring air, its main mirror, about 2.4 meters across, was meant to show details that no telescope on the ground could see. [3] The mirror had been tested many times before launch, and the tests had said that its shape was nearly perfect.
[4] Within weeks, the first images arrived, and stars that should have appeared as sharp points were surrounded by a fuzzy haze. [5] Engineers traced the problem to the edge of the mirror, which had been ground slightly too flat, by an amount about one-fiftieth the thickness of a sheet of paper. [6] The error had slipped through because a testing instrument used during the grinding had been assembled with one part slightly out of place, so it reported a flawed shape as correct.
[7] The mistake was tiny, but because it was known so exactly, it could be fixed without a new mirror. [8] So engineers designed new optics that bent the light by the same amount the other way, much as glasses fix the focus of an eye. [9] In December 1993, astronauts aboard the space shuttle Endeavour reached the telescope and, over five spacewalks, installed a new camera and a set of small correcting mirrors.
[10] The first pictures after the repair showed stars as crisp points of light, and the haze was gone. [11] In the years that followed, the telescope helped measure how fast the universe is growing and showed galaxies so far away that their light left them billions of years ago. [12] Its early failure is remembered along with its success, because measuring the flaw so exactly was what made the repair possible.
Draft summary: (1) Hubble was launched in 1990 to take sharp pictures from above the atmosphere. (2) The edge of its mirror had been ground slightly too flat, so its first images were blurry. (3) Because the flaw was measured precisely, astronauts installed correcting optics in 1993, and the pictures became sharp. (4) For example, Hubble later helped astronomers measure how fast the universe is expanding.
Bo's draft summary is too long. Which shorter version cuts the example in draft sentence 4 and keeps the central idea and its refinement?
- Hubble's mirror had a careless flaw that blurred its first images, but because it was measured precisely, astronauts corrected it in 1993.
- The edge of Hubble's mirror was ground slightly too flat, which blurred its first images, and the telescope later helped measure how fast the universe is expanding.
- Because Hubble's first images were blurry, the edge of its mirror was ground slightly too flat, and astronauts corrected the flaw in 1993.
- Hubble's mirror edge was ground slightly too flat, blurring its first images, but because the flaw was measured precisely, it was corrected in 1993.
The Telescope That Needed Glasses (article)
[1] When the Hubble Space Telescope was carried into orbit by the space shuttle Discovery in April 1990, astronomers expected the sharpest pictures of space ever taken. [2] From above the blurring air, its main mirror, about 2.4 meters across, was meant to show details that no telescope on the ground could see. [3] The mirror had been tested many times before launch, and the tests had said that its shape was nearly perfect.
[4] Within weeks, the first images arrived, and stars that should have appeared as sharp points were surrounded by a fuzzy haze. [5] Engineers traced the problem to the edge of the mirror, which had been ground slightly too flat, by an amount about one-fiftieth the thickness of a sheet of paper. [6] The error had slipped through because a testing instrument used during the grinding had been assembled with one part slightly out of place, so it reported a flawed shape as correct.
[7] The mistake was tiny, but because it was known so exactly, it could be fixed without a new mirror. [8] So engineers designed new optics that bent the light by the same amount the other way, much as glasses fix the focus of an eye. [9] In December 1993, astronauts aboard the space shuttle Endeavour reached the telescope and, over five spacewalks, installed a new camera and a set of small correcting mirrors.
[10] The first pictures after the repair showed stars as crisp points of light, and the haze was gone. [11] In the years that followed, the telescope helped measure how fast the universe is growing and showed galaxies so far away that their light left them billions of years ago. [12] Its early failure is remembered along with its success, because measuring the flaw so exactly was what made the repair possible.
Esme wants one sentence that keeps apart what the tests said before launch and what engineers later found. Which sentence does that accurately?
- The mirror's shape was nearly perfect, but the first images were blurry because a testing instrument had been assembled with a part out of place.
- Tests before launch reported that the mirror's shape was nearly perfect, but engineers found its edge slightly too flat and a testing instrument misassembled.
- Engineers found that the edge of the mirror was slightly too flat because a testing instrument had been assembled with one part out of place.
- Tests before launch reported that the mirror's shape was nearly perfect, but engineers found that the whole mirror was badly misshapen and had to be replaced.
How a Phone Knows Where It Is (article)
[1] Many people picture a phone's map app sending a signal up to a satellite, which then works out where the phone is and sends the answer back down. [2] The Global Positioning System, run by the United States, works almost the other way around. [3] A receiver in a phone or car never sends anything to the satellites at all, and it only listens to signals that the satellites broadcast all the time.
[4] At least twenty-four GPS satellites circle the Earth about 20,000 kilometers up, spaced so that several are in view from almost any spot on the planet. [5] Each satellite carries very exact atomic clocks and keeps sending out the time and its own position. [6] A receiver notes when each signal arrives, and because radio signals travel at the speed of light, the delay tells it how far away that satellite is. [7] Knowing its distance from several satellites at once, the receiver can work out the single point where all those distances meet.
[8] Three satellites would be enough if the receiver had a perfect clock, but the clock in a phone is far less accurate than the atomic clocks overhead. [9] That matters because light travels about 300 meters in a millionth of a second, so a tiny timing error becomes a large error in position. [10] The receiver solves the problem by using a fourth satellite, whose signal lets it calculate its own clock error along with its location.
[11] Engineers also set the satellite clocks to allow for small effects that Albert Einstein's ideas about time predict, which would otherwise make positions drift by kilometers each day. [12] The result is that an ordinary receiver can usually find its position to within a few meters, using only the timing of signals it hears. [13] In GPS, finding a place turns out to be mostly a matter of measuring time.
Jun is writing one sentence that keeps apart what many people picture and what GPS actually does. Which sentence does that?
- Many people naively picture a phone signaling a satellite for its location, but a GPS receiver only listens to signals the satellites broadcast.
- Many people picture a phone signaling a satellite for its location, but a GPS receiver only listens to signals that the satellites broadcast.
- A GPS receiver only listens, timing the signals that the satellites broadcast all the time to find its own position.
- A phone signals a satellite, which works out the phone's location and sends it back, using signals it broadcasts all the time.
Which single sentence would give Kira both the article's central idea and the way the article refines it?
- A GPS receiver finds its position by timing signals from satellites, and because its own clock is imprecise, it uses a fourth satellite to correct the timing.
- A GPS receiver finds its position by timing broadcast signals from several satellites and working out the single point where those distances meet.
- A GPS receiver cleverly finds its position by timing signals from satellites, and a fourth satellite neatly makes up for the receiver's poor clock.
- A phone's clock is far less accurate than the atomic clocks overhead, so a fourth satellite lets the receiver calculate its own clock error.
How a Phone Knows Where It Is (article)
[1] Many people picture a phone's map app sending a signal up to a satellite, which then works out where the phone is and sends the answer back down. [2] The Global Positioning System, run by the United States, works almost the other way around. [3] A receiver in a phone or car never sends anything to the satellites at all, and it only listens to signals that the satellites broadcast all the time.
[4] At least twenty-four GPS satellites circle the Earth about 20,000 kilometers up, spaced so that several are in view from almost any spot on the planet. [5] Each satellite carries very exact atomic clocks and keeps sending out the time and its own position. [6] A receiver notes when each signal arrives, and because radio signals travel at the speed of light, the delay tells it how far away that satellite is. [7] Knowing its distance from several satellites at once, the receiver can work out the single point where all those distances meet.
[8] Three satellites would be enough if the receiver had a perfect clock, but the clock in a phone is far less accurate than the atomic clocks overhead. [9] That matters because light travels about 300 meters in a millionth of a second, so a tiny timing error becomes a large error in position. [10] The receiver solves the problem by using a fourth satellite, whose signal lets it calculate its own clock error along with its location.
[11] Engineers also set the satellite clocks to allow for small effects that Albert Einstein's ideas about time predict, which would otherwise make positions drift by kilometers each day. [12] The result is that an ordinary receiver can usually find its position to within a few meters, using only the timing of signals it hears. [13] In GPS, finding a place turns out to be mostly a matter of measuring time.
Draft summary: (1) A GPS receiver does not signal the satellites; it only listens to their broadcasts. (2) It times each signal to find its distance from several satellites. (3) Because its clock is imprecise, it uses a fourth satellite to correct its timing error. (4) For example, an error of a millionth of a second would put it about 300 meters off.
Luz must shorten this draft summary. Which version cuts the example and still keeps the central idea and its refinement?
- A GPS receiver only listens, timing satellite signals to find its distances, and an error of a millionth of a second would put it about 300 meters off.
- A GPS receiver only listens, timing satellite signals to find its distances, and a fourth satellite corrects the error from its imprecise clock.
- A GPS receiver only listens, timing satellite signals to find its distances, and a fourth satellite makes up for its cheap, sloppy clock.
- Because a receiver's clock is imprecise, it uses a signal from a fourth satellite to correct its own timing error.
What Lewis and Clark Found (article)
[1] In 1803, the United States bought the vast Louisiana Territory from France, and President Thomas Jefferson soon sent an expedition to explore it. [2] He chose Meriwether Lewis to lead the group, and Lewis asked William Clark, a former army officer, to share the command. [3] Jefferson hoped above all that the explorers would find a water route across the continent, with the Missouri River leading close to a river that flowed to the Pacific and only a short carry over the mountains between them.
[4] The expedition left the St. Louis area in May 1804 and spent its first summer pushing boats up the Missouri against a strong current. [5] The group spent the winter near the villages of the Mandan and Hidatsa people, in what is now North Dakota. [6] There, Sacagawea, a Shoshone woman, joined the expedition with her husband, and her knowledge of the Shoshone language later helped the explorers obtain horses.
[7] When the explorers reached the headwaters of the Missouri in August 1805, they did not find a short carry to a westward river. [8] Instead, they saw range after range of the Rocky Mountains, which proved far wider and higher than Jefferson's maps had shown. [9] Crossing them on horseback took weeks of hard travel through snow, and only after reaching the Clearwater and Columbia rivers could they travel by canoe again. [10] They reached the Pacific coast in November 1805 and returned to St. Louis in September 1806.
[11] The expedition showed that the water route Jefferson had hoped for did not exist. [12] Yet the journey produced detailed maps of a region that few outsiders had mapped, along with descriptions of many plants and animals that scientists in the East had never recorded. [13] Its most lasting result was not the route it failed to find, but the knowledge it brought back about the land and the peoples who already lived there.
Noah needs one sentence that separates what Jefferson hoped from what the explorers found. Which sentence does that accurately?
- Jefferson hoped for a water route with only a short carry over the mountains, but the explorers found the Rockies far wider and no such route.
- Jefferson hoped for a water route with only a short carry over the mountains, but the explorers found the mountains impossible to cross and turned back.
- The Missouri led close to a river that flowed to the Pacific, with only a short carry over mountains far wider than the maps showed.
- Jefferson foolishly hoped for a water route with only a short carry over the mountains, but the explorers found the Rockies far wider and no such route.
Pia wants one sentence that holds the central idea and the way it is refined. Which sentence does that?
- Sent by Jefferson to find a water route to the Pacific, Lewis and Clark found none, but they brought back maps and knowledge of the land and its peoples.
- In 1804, President Jefferson sent Lewis and Clark up the Missouri River to explore the new Louisiana Territory and to find a water route to the Pacific Ocean.
- The expedition's most lasting result was not a route but knowledge, including maps and descriptions of plants, animals and peoples.
- Sacagawea, a Shoshone woman, joined the expedition in its first winter, and her knowledge of the Shoshone language later helped the explorers obtain horses.
Black Blizzards on the Plains (article)
[1] In the late 1800s, settlers on the dry southern Great Plains heard a hopeful saying, rain follows the plow, meaning that breaking up the prairie would somehow bring more rain. [2] A string of wet years seemed to prove it, and in the early 1900s farmers plowed up millions of acres of native grass to plant wheat, especially when wheat prices rose during World War I. [3] The deep-rooted prairie grasses that had held the soil in place for thousands of years were replaced by fields that lay bare after the harvest.
[4] In the early 1930s, a severe drought struck the region, and the crops withered in the fields. [5] With no grass to hold it, the dry topsoil lifted into the wind and rolled across the land in towering dust storms that people called black blizzards. [6] On April 14, 1935, a day remembered as Black Sunday, one of the worst storms turned the afternoon sky as dark as night across parts of Oklahoma and Texas. [7] Dust from the plains drifted as far as the cities of the East Coast.
[8] The drought was the trigger, but scientists who studied the disaster concluded that the way the land had been farmed made it far worse. [9] Rain had never followed the plow, since the wet years had simply been part of a natural cycle, and plowing had removed the grass that protected the soil during the dry ones.
[10] In 1935, Congress created the Soil Conservation Service, led by the scientist Hugh Hammond Bennett, to teach farmers ways to keep their soil in place. [11] Farmers learned to plow along the curves of the land instead of in straight lines, to leave crop stubble on their fields, and to plant rows of trees as windbreaks. [12] These practices, together with the return of rain later in the decade, helped bring the dust storms to an end.
Which one sentence would Ren use to give the article's central idea and its refinement?
- The 1930s dust storms began with a drought, but greedy farmers made them far worse by plowing up the prairie grass that held the soil.
- The 1930s dust storms began with a drought, but plowing that had stripped away the prairie grass holding the soil made them far worse.
- On April 14, 1935, a day remembered as Black Sunday, a dust storm turned the afternoon sky as dark as night across parts of Oklahoma and Texas.
- In the 1930s, a severe drought on the southern Great Plains made crops wither and sent the dry topsoil blowing away in huge dust storms.
Black Blizzards on the Plains (article)
[1] In the late 1800s, settlers on the dry southern Great Plains heard a hopeful saying, rain follows the plow, meaning that breaking up the prairie would somehow bring more rain. [2] A string of wet years seemed to prove it, and in the early 1900s farmers plowed up millions of acres of native grass to plant wheat, especially when wheat prices rose during World War I. [3] The deep-rooted prairie grasses that had held the soil in place for thousands of years were replaced by fields that lay bare after the harvest.
[4] In the early 1930s, a severe drought struck the region, and the crops withered in the fields. [5] With no grass to hold it, the dry topsoil lifted into the wind and rolled across the land in towering dust storms that people called black blizzards. [6] On April 14, 1935, a day remembered as Black Sunday, one of the worst storms turned the afternoon sky as dark as night across parts of Oklahoma and Texas. [7] Dust from the plains drifted as far as the cities of the East Coast.
[8] The drought was the trigger, but scientists who studied the disaster concluded that the way the land had been farmed made it far worse. [9] Rain had never followed the plow, since the wet years had simply been part of a natural cycle, and plowing had removed the grass that protected the soil during the dry ones.
[10] In 1935, Congress created the Soil Conservation Service, led by the scientist Hugh Hammond Bennett, to teach farmers ways to keep their soil in place. [11] Farmers learned to plow along the curves of the land instead of in straight lines, to leave crop stubble on their fields, and to plant rows of trees as windbreaks. [12] These practices, together with the return of rain later in the decade, helped bring the dust storms to an end.
Draft summary: (1) Settlers believed rain would follow the plow, and farmers plowed up the prairie grass to plant wheat. (2) When drought struck in the 1930s, the bare topsoil blew away in huge dust storms. (3) For example, on Black Sunday in 1935, a storm turned the sky as dark as night. (4) The Soil Conservation Service then taught farmers ways to protect their soil, such as windbreaks.
Zee has to cut this draft summary down. Which shorter version removes the example and keeps the central idea and its refinement?
- Farmers who believed rain would follow the plow stripped the prairie grass, and on Black Sunday in 1935 a dust storm turned the sky as dark as night.
- Because the dust storms blew away the topsoil, farmers who believed rain would follow the plow stripped the prairie grass, and new methods were taught.
- Farmers who believed rain would follow the plow stripped the prairie grass, so drought in the 1930s blew the bare soil away, and new methods were taught to protect it.
- Farmers who foolishly believed rain would follow the plow stripped the prairie grass, so when drought struck, the bare soil blew away and wiser methods were taught.