The big idea and how each part backs it up
Grade 8 Reading Worksheet
Circle the best answer.
Read this first
The Canal and the Mosquito (article)
[1] Cutting a canal across Panama looked like a job for engineers, but it was also a battle against disease. [2] A French company began digging in 1881, but within eight years it gave up, beaten by landslides, floods, and fevers that took thousands of lives.
[3] When the United States took over in 1904, doctors had learned that mosquitoes spread yellow fever and malaria. [4] Colonel William Gorgas ordered crews to drain standing water, spray oil on ponds, and screen buildings. [5] Within a few years, yellow fever had vanished from the Canal Zone, and far fewer workers fell ill with malaria.
[6] The engineers still faced the problem of the mountains. [7] They chose locks instead of a sea-level channel, so ships are lifted about 85 feet to a lake and lowered again on the far side. [8] A huge dam at Gatun made that lake, which carried ships across the middle of the isthmus and saved years of digging.
[9] The canal opened in 1914 and cut thousands of miles from the voyage between the Atlantic and Pacific oceans. [10] Historians note that the project worked only after health and engineering were solved together. [11] Tens of thousands of workers from the Caribbean and elsewhere did the digging and building, often in dangerous conditions.
Esme reads the article. First say its central idea in one sentence of your own. Then choose the statement that matches it best.
- The United States controlled yellow fever and malaria in Panama by draining standing water and screening buildings.
- This article describes how the Panama Canal was planned, dug, and finished between the 1880s and 1914.
- The Panama Canal was finished only because disease control and engineering design were solved together.
- The French company failed because it ignored disease, so any country that fights mosquitoes can finish a canal.
Noah asks what supporting idea paragraph 3 adds to the central idea. Which choice puts it in new words?
- Doctors learned that mosquitoes spread yellow fever and malaria, and crews drained pools and screened buildings to stop them.
- Engineers chose locks because a sea-level channel was impossible to dig, and no later canal has used a different design.
- Instead of digging through the mountains, the engineers lifted ships up to a lake and down again, using locks and a dam.
- A dam at Gatun made a lake that carried ships across the middle of the isthmus.
Pia asks how paragraph 4 relates to the central idea. Which choice describes it?
- It explains how mosquito control made the work site safe enough for the building to continue, and why the first attempt had failed.
- It repeats that the first attempt failed because of fever and floods, as the first paragraph already said.
- It shows that medicine mattered more to the canal than engineering did, since the mosquito work came before the locks and the dam.
- It gives the result and the lesson: the canal opened, and historians say it worked only because health and engineering came together.
When the Prairie Blew Away (article)
[1] In the 1930s, huge dust storms swept across the southern Great Plains, and some darkened skies as far away as Washington, D.C. [2] Drought was part of the cause, but it was not the whole story.
[3] During the 1910s and 1920s, high wheat prices and new tractors had led farmers to plow millions of acres of native prairie. [4] The deep roots of prairie grass had held the soil in place through earlier droughts. [5] When the rain stopped in the early 1930s, the bare, plowed fields dried to powder, and strong winds lifted it into the air.
[6] Families whose crops failed often could not pay their debts, and many left their farms for California and other states. [7] The storms also harmed health, since the fine dust caused breathing problems that people called dust pneumonia. [8] On April 14, 1935, a storm known as Black Sunday turned afternoon into darkness across several states.
[9] The federal government responded by teaching farmers to plow along the curves of the land, to leave crop stubble in the fields, and to plant rows of trees as windbreaks. [10] In 1935, it created the Soil Conservation Service to guide these practices. [11] When the rains returned in the late 1930s, the improved methods helped the soil stay in place. [12] Historians conclude that the Dust Bowl came from drought combined with farming methods that left the land unprotected.
Ren reads the article. First say its central idea in one sentence of your own. Then choose the statement that matches it best.
- A long drought in the early 1930s dried the plowed fields to powder, and strong winds carried the dust across the Great Plains and far beyond them.
- On April 14, 1935, a storm called Black Sunday turned the afternoon dark across several states, and people struggled to breathe in the dust.
- Drought alone did not cause the Dust Bowl; plowing away the prairie grass turned a dry spell into a disaster, and conservation helped the land recover.
- Farmers caused the Dust Bowl by plowing too much, and the drought had almost nothing to do with it, so the weather deserves little blame.
Luz asks what supporting idea paragraph 2 adds to the central idea. Which choice puts it in new words?
- Prairie grass roots could have stopped the dust storms, even in the driest years, if farmers had left the grass in place in 1930.
- Families lost their crops and their savings, and many moved west to California and other states.
- High wheat prices and new tractors led farmers to plow millions of acres of native prairie during the 1910s and 1920s, before the drought began.
- Farmers had plowed up the native grass whose deep roots once held the soil, so when the rain stopped, the loose soil blew away.
Bo asks how paragraph 4 relates to the central idea. Which choice describes it?
- It explains why bare fields blew away once the rain stopped and the deep prairie roots were gone, leaving loose dust for the winds to lift.
- It argues that the Soil Conservation Service ended the dust storms in the late 1930s, which shows how much one government office can do.
- It gives the response and the conclusion: new practices kept the soil in place, and historians blame drought together with unprotected land.
- It repeats that drought was part of the cause, as the opening paragraph already said, and then adds that farmers also suffered losses.
From Cowpox to Vaccine (article)
[1] In the 1790s, smallpox was one of the most feared diseases in the world, and survivors were often left scarred or blind. [2] Some families protected themselves by inoculation, in which a doctor gave a healthy person a small dose of smallpox matter, but the method could cause a severe case of the disease.
[3] Edward Jenner, an English country doctor, noticed that milkmaids who had caught the mild disease cowpox seemed to escape smallpox. [4] Jenner suspected that cowpox protected people, but a suspicion was not proof. [5] In 1796, he placed matter from a cowpox sore into small cuts on the arm of an eight-year-old boy named James Phipps. [6] Weeks later, Jenner exposed the boy to smallpox, and the boy stayed healthy. [7] Modern rules would forbid such an experiment on a child, but at the time it gave the first strong support for Jenner's idea.
[8] Jenner repeated the test on other people and published his results in 1798. [9] Many doctors resisted at first, partly because nobody could explain why cowpox worked. [10] That explanation came only decades later, when scientists learned that germs cause disease and that the body can learn to defend itself against them.
[11] Even without the explanation, the practice of vaccination spread across Europe and beyond. [12] In 1980, the World Health Organization declared that smallpox had been wiped out, the first human disease to disappear in this way.
Kira asks what supporting idea paragraph 3 adds to the central idea. Which choice puts it in new words?
- Jenner published his results in 1798 after repeating the test on other people, and his report reached doctors in many countries.
- Doctors refused to use vaccination until germ theory was proved, so it did not spread in Jenner's lifetime.
- Jenner shared his results, but doubt remained among doctors until later science explained why the method worked.
- Jenner linked cowpox to smallpox, tested the link on a boy, and saw the boy stay healthy.
Jun asks how paragraph 4 relates to the central idea. Which choice describes it?
- It shows the result: vaccination spread even without an explanation, and later it helped end smallpox worldwide.
- It repeats that Jenner's experiment on a child would be forbidden under modern rules.
- It describes the risky method families used before Jenner, which sometimes caused a severe case of the disease, and why they accepted that risk.
- It argues that Jenner alone ended smallpox, with no help from any later scientist, because his test came first.
Cities Built by Animals (article)
[1] A coral reef looks like rock, but its builders are animals, most of them smaller than a pencil eraser. [2] Each coral polyp makes a hard cup of limestone around its body, and when many polyps live side by side, their cups join into a reef. [3] Reefs cover less than one percent of the ocean floor, yet they shelter about a quarter of all marine species.
[4] Most reef-building corals depend on a partnership. [5] Tiny algae live inside the polyp's tissue and use sunlight to make sugars, which feed the coral. [6] In return, the polyp provides the algae with shelter and nutrients. [7] The algae also give corals their color.
[8] The partnership is fragile. [9] When the water becomes too warm, the polyps expel their algae, the coral turns pale, and it starves unless cooler water returns soon. [10] This is called bleaching, and large areas of reef have bleached during several recent heat waves.
[11] Reefs also protect coastlines by breaking waves before they reach shore, so damaged reefs mean greater storm damage for the people who live nearby. [12] Researchers are therefore testing ways to protect reefs, such as growing heat-tolerant corals in nurseries and replanting them.
Ari reads the article. First say its central idea in one sentence of your own. Then choose the statement that matches it best.
- Reefs, built by animals that depend on a fragile partnership with algae, shelter ocean life and protect coasts, so warming water that breaks the partnership threatens both.
- Coral polyps and algae form a partnership in which the algae make sugars for the coral and the coral gives the algae shelter, and the algae also give the coral its color.
- Reefs cover less than one percent of the ocean floor, yet they shelter about a quarter of ocean species, which makes them crowded with life.
- Coral reefs will disappear completely within a few decades, because heat waves have bleached the reefs of the whole world and nothing can be done to save them.
Tala asks how paragraph 4 relates to the central idea. Which choice describes it?
- It explains how algae inside the polyps use sunlight to feed the coral, and why the coral loses its color when it is stressed.
- It widens the stakes: damaged reefs would leave coasts more exposed, so researchers are testing ways to protect them.
- It argues that growing heat-tolerant corals in nurseries will save the world's reefs, so researchers no longer need to protect the water.
- It repeats that reefs shelter about a quarter of marine species, as the first paragraph already said, and then lists more animals.