Electricity's Long Journey
1 Think of a time when you watched a movie with your family, played online games with your friends, or cooked a waffle in a waffle maker. You needed electricity for all of these activities. Where does electricity come from? How does it get to your waffle maker?
2 Electricity comes from power plants. It is made using coal, wind, nuclear energy, water, or natural gas. The electricity then goes on a long journey. It gets stronger and weaker along the way.
3 The journey begins as the electricity is sent through giant transformers. These machines give the electricity the extra power it needs to move long distances. Without this power boost, electricity doesn't move very well. Then, the electricity flows through transmission lines. Transmission lines are cables that stretch across many miles. You may have seen these lines crossing hills and fields. They are supported by large metal towers that are called pylons.
4 Next, the electricity is sent into a substation. The substation has transformers that lower the electricity's power so it can flow through smaller power lines. Then, the electricity moves along the wires you see around your neighborhood.
5 After this, the electricity goes through smaller transformers at the tops of some power poles. These little transformers lower the energy even more. Finally, the electricity moves through connecting lines and into your home.
6 The next time you plug something in, it might spark your memory. Maybe, then, you will remember how far electricity travels. Which detail from the text explains what happens to electricity right before it enters people's homes?
A.
"You needed electricity for all of these activities." (paragraph 1)
B.
"The journey begins as the electricity is sent through giant transformers." (paragraph 3)
C.
"Then, the electricity moves along the wires you see around your neighborhood." (paragraph 4)
D.
"These little transformers lower the energy even more." (paragraph 5)
D. "These little transformers lower the energy even more." (paragraph 5)
High-Speed Animals
1 What are the fastest animals? The cheetah is the fastest land animal. The pronghorn antelope is the second fastest land animal. But the peregrine falcon is the fastest animal in the world. All of these animals are fast because their bodies are built for speed.
2 A cheetah can run up to 70 miles per hour. Because it has large lungs and nostrils, a cheetah can breathe easily as it speedily runs. A cheetah's body is small and light, so its strong muscles don't have to carry much weight. Since it has long legs and a long spine, its steps are very big. A cheetah uses its tail for balance. As a result, the cheetah doesn't slide or fall when it quickly changes direction.
3 Cheetahs run fast to catch prey, but pronghorn antelopes run fast to escape predators. A pronghorn can run about 61 miles per hour. Like cheetahs, pronghorn antelopes are very light and strong. A pronghorn can make big leaps when it runs because of its long legs. As a result of its large lungs, the pronghorn can take in as much air as it needs while running.
4 The peregrine falcon moves at over 200 miles per hour when it dives toward prey. While diving, it holds its wings close and lengthens its body. As a result of this position, it can cut through the air at high speed—almost like a jet plane. Its strong heart and lungs help it to keep breathing as it dives. Which detail from the text explains how a cheetah's body is created to run quickly?
A.
"All of these animals are fast because their bodies are built for speed." (paragraph 1)
B.
"Since it has long legs and a long spine, its steps are very big." (paragraph 2)
C.
"Its strong heart and lungs help it to keep breathing as it dives." (paragraph 4)
D.
"While diving, it holds its wings close and lengthens its body."
B. "Since it has long legs and a long spine, its steps are very big." (paragraph 2)
Chihuahuas and Saint Bernards
1 Dogs are the world's most popular pet. With over 400 dog breeds in existence, there are lots of great dogs to choose from. But how do you choose? Start by looking at the characteristics of different dog breeds. Think about the size of a dog, its personality, and how it looks.
2 Chihuahuas are known as a "toy breed" because they are very small. Chihuahuas weigh about 5 pounds and grow up to 8 inches tall. In contrast, Saint Bernards are huge. This friendly giant can weigh up to 200 pounds and stand about 29 inches tall. A chihuahua would be happy living in a small apartment, but a Saint Bernard needs more space.
3 Dogs have personalities, similar to humans. Both chihuahuas and Saint Bernards are loyal and friendly. They like to please the humans they live with. Saint Bernards are watchful and patient with children, like a babysitter. Chihuahuas are also good with children. Even though the chihuahua is small, it can act like a big dog by barking a lot. Chihuahuas are distrusting of strangers. Saint Bernards don’t bark very much and are friendly with everyone.
4 Chihuahuas have short hair that doesn't get very dirty, but Saint Bernards have thick, curly coats that pick up dirt. Saint Bernards need to have their coats brushed every week to keep them clean. Drooling is a characteristic of some dogs, including the Saint Bernard, but Chihuahuas drool very little. Select the correct text.
Which sentence shows that Saint Bernards enjoy being around all people?
3 Dogs have personalities, similar to humans. Both Chihuahuas and Saint Bernards are loyal and friendly. They like to please the humans they live with. Saint Bernards are watchful and patient with children, like a babysitter. Chihuahuas are also good with children. Even though the Chihuahua is small, it can act like a big dog by barking a lot. Chihuahuas are distrusting of strangers. Saint Bernards don't bark very much and are friendly with everyone.
The sentence that shows that Saint Bernards enjoy being around all people is:
"Saint Bernards don't bark very much and are friendly with everyone."
Sockeye Salmon Lifecycle
1 Sockeye salmon live in the Pacific Ocean. During their life cycle, these fish grow, change, and travel great distances.
2 The first stage in the life cycle begins in mountain streams where salmon lay their orange eggs. The eggs are hidden under small stones. Stream beds contain thousands of eggs that will all hatch at about the same time.
3 At the second stage, the eggs hatch. The young salmon are called "alevins." They look like tadpoles, or eggs with tails. The alevins stay hidden at the bottom of the stream.
4 After four to six weeks, the salmon enter the third stage and are called "fry." The young fry are still very small. They stay in rivers close to where they were born. During this time, they eat and grow. Soon, they begin to look more like adult fish.
5 After a few years of eating and growing, the salmon become teenagers. They are called "smolts." During this fourth stage, the smolts begin their journey downstream to the ocean. The smolts spend time in the place where freshwater from the river mixes with the salty ocean water. This helps them get used to living in salt water.
6 At the fifth stage, the salmon live in the ocean and grow into adults. They stay there for one to four years, eating smaller fish and growing.
7 In the last stage of the life cycle, the adult salmon swim up the streams they swam down as smolts. They lay eggs in the same spot where they hatched years earlier. Which detail from the text explains why smolts spend time where the river and ocean mix?
A.
"Stream beds contain thousands of eggs that will all hatch at about the same time." (paragraph 2)
B.
"During this time, they eat and grow." (paragraph 4)
C.
"This helps them get used to living in salt water." (paragraph 5)
D.
"They lay eggs in the same spot where they hatched years earlier." (paragraph 7)
C. "This helps them get used to living in salt water." (paragraph 5)
Animals that Work Together
1 Living in groups helps animals survive. Animals that live in groups are called social animals. Meerkats and honeybees are both social animals.
2 Living in groups helps animals protect themselves. Meerkats are social animals that live in Africa. They spend their days looking for food and caring for their young. Meerkats also protect each other from predators. Some meerkats act like guards. When they see a predator, they let out a loud squeal. This causes other meerkats to run into their burrows to hide. Sometimes meerkats work as a team to protect themselves. When a predator comes near a gathering of meerkats, the meerkats stand close together and hiss loudly. This fools the predator into thinking it is facing a larger animal. As a result, the predator will often run away.
3 Living in groups also helps animals get enough to eat. Honeybees cooperate to find food. Worker bees gather pollen and nectar from flowers. When they find a good source of pollen and nectar, they do a wiggle-dance so that other worker bees can find the food source. More worker bees gathering food leads to more food for the whole colony. Worker bees share the food they gather with the other bees in the colony. Select the correct text.
Which sentence shows that living with other meerkats helps meerkats protect themselves?
1 Living in groups helps animals survive. Animals that live in groups are called social animals. Meerkats and honeybees are both social animals.
2 Living in groups helps animals protect themselves. Meerkats are social animals that live in Africa. They spend their days looking for food and caring for their young. Meerkats also protect each other from predators. Some meerkats act like guards. When they see a predator, they let out a loud squeal. This causes other meerkats to run into their burrows to hide. Sometimes meerkats work as a team to protect themselves. When a predator comes near a gathering of meerkats, the meerkats stand close together and hiss loudly. This fools the predator into thinking it is facing a larger animal. As a result, the predator will often run away.