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100
The department of Fish and Wildlife gives each participating classroom 500 salmon eggs. When the eggs hatch, the children care for the baby salmon and learn about their life cycle. When the salmon are big enough, the class goes on a field trip to release the salmon into a stream or river. What is the main idea of this paragraph?
School children are raising salmon.
100
Rabbits live together in burrows. Their babies are born blind and without fur. Hares live alone above ground. Their babies are born with fur and are not blind. In addition, hares are usually bigger than rabbits.
Rabbits and hares are not the same.
100
A shark may have up to 3,000 teeth at one time. Shark teeth grow in rows. When a shark loses a tooth, it is replaced by a new tooth from the row behind it. A shark may have over 20,000 teeth over the course of its life.
Sharks have a lot of teeth.
100
When beavers build a dam across a river, they dramatically change the landscape. The dam creates a pond or even a lake. Land that was once dry gets covered in water. The new lake becomes a home for birds, fish, and other kinds of wild life.
Beavers make dramatic changes to the environment.
100
The thick, white coat of the Arctic fox keeps it warm in freezing temperatures. It also help the fox to blend into the snowy landscape so that it can hide from predators and sneak up on prey without being seen.
The thick, white coat of the Arctic fox has two important jobs.
200
One day in Switzerland a man names George de Mestral decided to take his dog for a walk. When he got back to his house, he saw that there were many small burrs clinging to his dog's fur. He examined how the burrs were sticking under a microscope and ended up using what he saw to invent Velcro!
The idea for Velcro came from nature.
200
Giant pandas live in bamboo forests in China. The average giant panda eats about 30 pounds of bamboo each day. Unfortunately, the forests are being cut down and the giant panda is losing its habitat.
Giant pandas are losing their habitat.
200
A mother octopus lays thousands of eggs in a den. Once the eggs are laid she guards them constantly and does not leave the den. When the eggs hatch, the tiny baby octopuses float away. Then the mother dies.
A mother octopus takes good care of her eggs.
200
In Australia, cattle and sheep ranches are called stations. Most stations are very big. A station may be so large that low-flying helicopters are used to herd the animals. You could drive for several days in one direction and never leave the station.
In Australia, cattle and sheep are raised on huge ranches called stations.
200
Before toothbrushes were invented, people cleaned their teeth with small twigs. The first toothbrushes were made from bones and bristles from boars, horse hairs, or even feathers. Today the bristles on most toothbrushes are made from nylon.
Before toothbrushes were invented, people used natural items to clean their teeth.
300
The Atacama Desert is located on a plateau in northern Chile. It almost never rains in the Atacama Desert, in fact there are some areas of the desert where rainfall has never been recorded. The average yearly rainfall in Atacama is just 1 millimeter. Nowhere else on earth is dryer than the Atacama Desert!
The Atacama Desert is the driest place on Earth.
300
Here is something fun to try. Lay an egg on its side and try to make it spin. If it is not hard-boiled the shifting liquid inside will make it spin poorly. If it is hard-boiled the solid inside will make it spin faster and longer.
You can tell if an egg is hard-boiled by spinning it.
300
Solar ovens use energy fromt he sun. When a family uses a solar oven to cook their food, they do not have to collect wood for fuel or spend money to buy fuel. Solar ovens are a good option for many families in developing countries.
In many developing countries, people are using solar ovens.
300
The Maasai people in East depend on their cattle for most of their food. They sell cattle to outsiders to p ay for the things they need. They spend most of their time tending to their cows.
The lives of the Maasai people are centered around their cattle.
300
It all started in 1904 at the St. Louis World's fair when an ice cream vendor ran out of dishes for his ice cream. A man named Ernest Hamwi was selling waffles in the booth next door. He helped his neighbor out by making cone-shaped waffles to hold the ice cream.
The ice cream cone was invented in 1904.
400
Troglobites live in total darkness for their entire lives. They live in caves and never come out. Some troglobites do not even have eyes! Troglobites include spiders, flatworms, cave fish and blind salamanders. What is the main idea of this paragraph?
Animals that live deep in a cave are called troglobites.
400
Incense cedar wood is used for making pencils because it does not break easily, but is soft enough to be sharpened without splintering. It also won't bend or warp in hot temperatures. Incense cedar trees are grown in California and Oregon.
Incense cedar wood is perfect for making pencils.
400
Guinea pigs may be pets in the United States, but in Peru, they are dinner. Guinea pigs are a good source of protein for many people who live in Peru. They can also be a much needed source of income for people who raise them to sell.
In Peru, many people eat guinea pigs.
400
Christopher Paolini was just 15 years old when he wrote the first draft to the fantasy book Eragon. His parents helped him to self-publish and to promote the book in schools and libraries. Three years later, Knopf Bloks for Young Readers asked Christopher's family if they could publish the book. Today, Eragon is a best seller.
Christopher Paolini became an author at a young age.
400
Julia Butterfly Hill climbed a giant redwood tree on December 10, 1997. She stayed in the tree, which was located in northern California, for nearly 2 years. Many people helped her by bringing her food and supplies. She did not come down until the logging company promised never to cut the tree down.
Julia Butterfly Hill lived in a giant redwood tree for 2 years to prevent it from being cut down.
500
Strong magnets are put into some roller coasters. They are also put into the end of the track. As the roller coaster approaches the end of the track, the attracting forces of the magnet bring the coaster to a gentle stop.
Some roller coasters use magnets to make them stop.
500
A pygmy marmoset monkey is only about 5 inches tall and weights just 4 ounces. The pygmy marmoset is smaller than any other kind of monkey. Pygmy marmosets live in the Amazon rain forest in South America.
The smallest monkey in the world is the pygmy marmoset monkey.
500
When most animals look into a mirror, they think that the reflection is another animal. A few animals do recognize themselves. They include: elephants, dolphins, chimps, and great apes.
Most animals do not recognize themselves in a mirror.
500
Kangaroos spend most of their time in groups called mobs. Kangaroos communicate with each other with clicks, cough, hisses, and growls. They also groom each other by picking dirt, insects, and dead skin from each other's fur.
Kangaroos are very social animals.
500
What is the main idea of this article?
Smartphones can be used in both good and bad ways.