A butterfly begins as an egg. The egg hatches into a larva, a caterpillar that eats and grows. The larva then forms a hard-shelled pupa called a chrysalis. Later an adult butterfly comes out. What happens right after the larva stage?

A science book says, "When a caterpillar stops eating, it sheds its skin one last time. Its hardened outer covering, called a chrysalis, then protects it while it changes into an adult." The chrysalis forms right after the caterpillar sheds its ___.

The Statue of Liberty is covered with thin sheets of copper, and it once looked shiny brown. Because the copper reacted with air and rain for about thirty years, a thin green layer formed on it. Why did the statue turn green?

The sun warms a lake, and water evaporates into the air as vapor. As the vapor rises, it cools. The cooled vapor condenses into tiny droplets that gather into clouds. Rain later falls. What happens right after the vapor cools?

A burner heats the air inside a hot air balloon. Heated air is lighter than the cooler air outside the balloon. As a result, the balloon lifts off the ground. According to the passage, why does the balloon rise?

Bakers mix yeast into bread dough. The yeast feeds on sugar in the dough and gives off carbon dioxide gas. The gas is trapped in bubbles, so the dough puffs up. Why does the dough rise?

Britain taxed tea sold in the colonies. Colonists in Boston said the tax was unfair because they had no vote in Parliament. In 1773 they boarded three ships and dumped the tea into the harbor. Why did the colonists dump the tea?

Read this paragraph. "Heavy rain fell all night. As a result, the river rose over its banks. Because the road was flooded, the school bus could not run." Which text structure does this paragraph use?

The Pony Express carried mail west by horse in 1860. Riders crossed the country in about ten days. In October 1861 the telegraph line reached California. The company closed two days later. What does the passage suggest is the reason the Pony Express ended?

Directions for planting a bean. Fill a cup with soil. Push the seed about an inch down. Water the soil until it is damp. Set the cup in a sunny window. Which step comes last?

A student lists the steps of an experiment. "First, pour the water. Next, add the salt. Then, stir the mixture. ___, record what you see." Which word best signals the last step?

A paragraph says, "A storm knocked out the power at the school. As a result, the class trip to the zoo was canceled." The paragraph gives the storm as the reason the trip was canceled.

Read the text: "When the town library became too small, volunteers collected donations for a new building. After enough money was raised, workers built a larger library with more shelves and reading tables." Why did the town build a larger library?

Read the steps: "First, rinse the seeds and place them on a damp paper towel. Next, fold the towel and put it in a plastic bag. Finally, keep the bag near a sunny window and check it each day." What is the next step after the seeds go on the towel?

Read the text: "A beaver’s front teeth never stop growing. Beavers chew wood often, which wears the teeth down and keeps them from becoming too long." How does chewing wood help beavers?

Read the text: "During the parade, dark clouds gathered. Soon rain began falling, so the marching band covered its instruments and moved under a tent." What caused the band to move under a tent?

Read the text: "To make recycled paper, workers mix old paper with water to form pulp. Then they spread the pulp in thin sheets and let it dry." True or False: The pulp is dried before it is spread into sheets.

Read the text: "Long ago, many people traveled west in covered wagons. The trip was slow because wagons had to cross rivers, climb mountains, and follow rough trails." Which detail best explains why the trip was slow?

Read the procedure: "Before painting a wooden birdhouse, sand the rough edges. Then wipe away the dust. After that, paint a thin first coat." Why should you wipe away the dust before painting?

Read the text: "A shadow changes during the day because the Sun appears to move across the sky. In the morning, shadows are long and point one way. At noon, they are shorter." What concept is explained in the text?