Honeybees store honey to feed the hive through winter. They also carry pollen from flower to flower as they feed. That pollen movement helps crops such as almonds and apples produce fruit. Which pair of ideas does the passage develop?

Sea otters eat urchins, which graze on kelp, so bays with otters keep their kelp forests. Otters have no blubber. Their dense fur traps air against the skin, holding in heat. Which detail supports the second main idea, that otters stay warm?

The Erie Canal opened in 1825 and linked the Hudson River to Lake Erie. Boats pulled by mules carried grain east and settlers west. Shipping costs fell, and New York City grew into the nation's busiest port. What is the best summary of the passage?

Bamboo grows faster than any other plant, with some kinds adding nearly a meter a day. Bamboo is also strong enough that builders use it for scaffolding. Which detail supports the idea that bamboo is strong?

Wildfires destroy homes and burn thousands of acres. Yet some pine cones open and drop their seeds only after fire's heat. Ash also returns nutrients to the soil. Which pair of ideas does the passage develop?

Rome's aqueducts carried water into cities on a gentle downhill slope, and some crossed valleys on stone arches. Rome's roads were built in layers of stone and gravel, so armies could march quickly. Which detail supports the idea about roads?

Peregrine falcons dive at over 200 miles per hour, faster than any other animal. In cities, tall buildings act like cliffs and pigeons are plentiful all year. What is the passage's second main idea?

Deserts get less than ten inches of rain a year. Desert plants such as the saguaro cactus store water in thick stems. Desert animals such as kangaroo rats stay in burrows by day and look for food at night. Which pair of ideas does the passage develop?

Volcanic ash breaks down into rich soil, so farms cluster near some volcanoes. Volcanoes also threaten those same farms with sudden eruptions. The passage develops two main ideas about volcanoes rather than one. True or False?

The Great Barrier Reef stretches over 1,400 miles and shelters thousands of species. Warmer water has bleached large parts of it, and workers now replant coral. Which pair of ideas does the passage develop?

Harriet Tubman escaped slavery in 1849 and then guided about seventy others north on the Underground Railroad. During the Civil War she also worked for the Union Army as a scout and a nurse. Which pair of ideas does the passage develop?

Sleep lets the body repair muscle and fight illness; wounds heal faster in good sleepers. Sleep also helps the brain store the day's learning; students who sleep nine hours recall more of a lesson. Which detail supports the second idea, about the brain?

Antarctica is the coldest continent, with temperatures that fall below minus 80 degrees Fahrenheit. It is also one of the driest places on Earth, since very little snow falls there each year. Which pair of ideas does the passage develop?

Some spiders spin webs to trap insects, while wolf spiders chase down prey instead. Both kinds use venom to subdue what they catch. Which detail supports the idea that the two kinds of spider hunt in different ways?

Mia wanted the garden to attract butterflies. She planted milkweed for caterpillars, added bright flowers for nectar, and placed shallow dishes of water near flat stones. By spring, many kinds of butterflies visited the garden. What is the main idea?

Read the passage: Electric buses are becoming more common in cities. They do not release exhaust from tailpipes, and they are quieter than many diesel buses. Some cities also save money on fuel because the buses run on electricity. What is the main idea?

A supporting detail is a fact, example, or reason that helps explain the main idea.

Read the passage: Each Saturday, Leo bakes bread with his grandfather. First they mix flour, water, yeast, and salt. Then they wait for the dough to rise. Finally, they shape and bake the loaves till they smell warm and sweet. What is the main idea?

Which sentence best states a main idea?

Read the passage: Many animals use camouflage to stay safe. A walking stick insect looks like a twig. A snowshoe hare turns white in winter to blend with snow. A flounder can match the color of the sandy ocean floor. What is the main idea?