Passage: "Sea otters eat sea urchins. Sea urchins eat kelp. When hunters removed most of the otters from a coast, urchin numbers grew and the kelp forests were eaten away." According to the passage, what caused the kelp forests to shrink?

Passage: "Wolves were returned to Yellowstone National Park in 1995. Elk began moving more often instead of grazing in one spot for long. As a result, young willows and aspens along the streams grew back." What effect did the elk's new behavior have?

Passage: "The Erie Canal opened in 1825. Boats could carry heavy loads across New York. Freight costs between Buffalo and New York City fell sharply. New York City's port grew busier." Quoting exactly, what happened to freight costs after the canal opened?

Passage: "Yeast gives off a gas as it feeds on the sugar in bread dough. The dough traps the bubbles, so the loaf rises." In this process, the rising of the dough is caused by the ___ that the yeast gives off.

Passage: "Gutenberg's printing press, built in the 1400s, printed pages far faster than copying by hand. Books became cheaper, and more people learned to read." True or False: the passage presents cheaper books as something that followed the press.

Passage: "Before 1869, going from the eastern states to California took months by wagon or by ship. The transcontinental railroad was finished that year. After it opened, the trip took about a week." How did the railroad affect travel time to California?

Passage: "Farmers plowed up the grasses of the southern Plains to plant wheat. The grass roots had held the soil in place. When drought came in the 1930s, the bare soil dried out and blew away in dust storms." Why did the wind carry off so much soil?

Passage: "In 1815 Mount Tambora erupted and threw ash and gas high into the air. Those particles blocked some sunlight. The next year was so cool that crops failed in Europe and North America." What connected the eruption to the failed crops?

Passage: "Beavers cut down small trees and build dams across streams. Water backs up behind a dam and spreads into a pond. Frogs, fish, and wading birds move into the new pond." What happens to the stream as a direct result of the dam?

Passage: "Edward Jenner noticed that milkmaids who had caught cowpox did not get smallpox. In 1796 he used material from a cowpox sore to protect a boy from smallpox. His work led to the first vaccine." What led Jenner to try cowpox as protection?

Passage: "Honeybees visit flowers to gather nectar. Pollen sticks to their hairy bodies. When a bee lands on the next flower, some pollen rubs off. That transfer lets the plant make seeds." Which sentence tells how pollen gets from a bee onto a flower?

Passage: "On a steep hillside, tree roots hold the soil together. Loggers cleared every tree from one slope. When the next heavy rains came, mud slid down that bare slope and buried the road below." According to the passage, why did the mud slide down?

Read: "Maya missed the bus because she stopped to help her younger brother find his backpack." What detail explains why Maya missed the bus?

Read: "The storm knocked down several branches. As a result, the trail was closed for repairs." What happened because of the storm?

Read: "While the volunteers cleaned the park, other volunteers painted the fence." What relationship does the word "while" show between the two actions?

Read: "Unlike her brother, who rushed through his chores, Elena checked each shelf twice before leaving the library." What relationship is shown between Elena and her brother?

Read: "First, the class planted seeds. Next, they watered the soil. Two weeks later, tiny green sprouts appeared." Which event happened last?

Read: "The old bridge was narrow and wooden. The new bridge is wider and made of steel." Which detail shows how the bridges are different?

Passage: "The museum was closed on Monday for cleaning. However, it opened early on Tuesday for a special exhibit." True or False: according to the passage, the museum stayed closed on Tuesday.

Read: "After reading about food waste, Jordan began packing only what he could finish for lunch." What relationship is shown in the sentence?