For some animals, being too slow can put them in danger. For sloths, though, moving slowly is a way to protect themselves. Sloths are furry animals with long arms. They live in trees in the warm forests of South America and Central America. Sloths hardly move at all. They actually stay so still that green plants called algae grow on their fur! The algae help the sloths hide in the green leaves around them. Being slow also helps sloths in another way. Animals like hawks and big cats often spot animals that are moving quickly. They hardly notice the slow-moving sloths.

A volcano is an opening in the earth above a pool of melted rock. Volcanoes usually look like mountains. But volcanoes can erupt, which sends the melted rock out of the volcano. Not all volcanic eruptions are the same. Some volcanoes shoot rocks, ash, and gas high into the air. Mount St. Helens in Washington, for example, erupted like this in 1980. Other volcanoes erupt differently. Instead of shooting out rocks, they pour out red-hot melted rock, or lava. The lava flows out and runs down the sides of the volcano. Mauna Loa in Hawaii erupts in this way.

Soccer players learn many skills when playing soccer. Soccer players learn how to dribble and pass the ball. They also learn how to control the ball so they can eventually score. Most importantly, soccer players learn how to work together with their teammates.

Before the Europeans came, women in North America had more power and freedom than women in Europe or Asia. Women owned their own houses. They could get divorced if they wanted to. They didn't lose their children if they did get divorced.

Pluto is an icy dwarf planet in the Kuiper belt, a ring of bodies beyond the orbit of Neptune. It was the first and the largest Kuiper belt object to be discovered. Pluto was discovered by Clyde Tombaugh in 1930 and declared to be the ninth planet from the Sun.

Bats are known for flying around at night and sleeping during the day. You may have seen pictures of bats sleeping upside down in caves. Bats have other daytime resting places, too. They sleep in trees, in old buildings, and even under bridges. More than a million bats sleep under one bridge in Austin, Texas. This colony, or group, contains about as many bats as there are people in the city!

Gravity is the force that makes things fall to Earth. You can't see or touch it, but without gravity, life on Earth would be quite different. Everything would simply float away. If you jumped up, you would fly off into space. If you threw a baseball, it would never come down. Gravity is also the force that keeps the Earth orbiting around the sun. So, without gravity, the Earth might float away, too.

Native people in early North America liked to play games. Their favorite games were played with a stick and a ball, like lacrosse. In lacrosse the rule is that you can't touch the ball with your hands. You catch the ball in a net on the end of a stick and use the stick to throw the ball.

People in early North America ate only wild foods that they could hunt or gather. Inuit people ate a lot of fish and seal meat, and gathered seaweed. Pueblo people ate cactus fruit and pine nuts, and hunted rabbits and birds. Cree people ate fish with wild rice that they gathered in the wetlands around the Great Lakes.

The Sun is the star at the center of the Solar System. It is a nearly perfect sphere of hot plasma, with internal convective motion that generates a magnetic field via a dynamo process. It is by far the most important source of energy for life on Earth.

A female kangaroo has a special fold of skin that forms a pouch. The pouch is like a large pocket on its stomach. When a baby kangaroo, or joey, is born, it climbs into its mother's pouch. At birth, a joey is only about one inch long. It needs to stay in the pouch so it can grow more. After several months, the joey has grown enough to leave the pouch for short periods of time. By the time the joey is ten months old, it is ready to leave the pouch for good.

Earthquakes are caused when the plates of the Earth's crust move. Earthquakes happen along "fault lines" in the earth’s crust. When the plates in the Earth suddenly shift, the Earth will begin to shift, shake or tremble.

Alex scored 8 points for his baseball team. He struck out 5 players. He hit 2 home runs and drove in 6 more runs. Alex was declared Most Valuable Player of the game.

Thomas Alva Edison is remembered because of the huge number things he invented which are still used today. He invented the light bulb. The storage battery was invented by him. Motion pictures (movies) were another of his inventions. The storage battery was invented by him.

For many years scientists have studied our own solar system. But until the last few years, we knew of no other solar systems. This may seem surprising, as the Sun is one of about 200 billion stars (or perhaps more) just in the Milky Way galaxy alone.

Many people believe that the dinosaurs were killed when an asteroid hit the earth. An asteroid is a small, rocky object that orbits the sun. However, some scientists now think that the asteroid wasn't the only cause. Some scientists think that there were climate changes before the asteroid hit. They believe that these climate changes killed some animals and plants that dinosaurs needed for food. Also, some scientists believe there may have been harmful gases in the air that killed many dinosaurs. So, when the asteroid hit, it made things even worse for the dinosaurs.

Scientists can measure the intensity of an earthquake. They use an instrument called the Richter scale. The Richter scale compares the strength of different earthquakes. Earthquakes below 2.0 usually can’t be felt. Earthquakes over 5.0 on the scale can cause damage. A magnitude 7.0 is a major earthquake and can cause tremendous damage.

The game is played with 2 teams. Each team consists of 5 players on the court at a time. The object of the game is to outscore your opponent by shooting the ball into your basket and preventing them from putting the ball into theirs. The ball can be advanced up the floor with the hands only, either by dribbling or passing to teammates.

Martin Luther King Jr. was one of America's most important civil rights leaders. He inspired many with his famous, "I have a dream" speech. He believed in using non-violent methods to achieve his dream of racial integration. He was assassinated at age 39.

At the core of the sun, gravitational attraction produces immense pressure and temperature, which can reach more than 27 million degrees Fahrenheit (15 million degrees Celsius). Hydrogen atoms get compressed and fuse together, creating helium.

Alligators are surprisingly helpful mothers. A female alligator builds a nest for her eggs on the shore. After she lays her eggs, she covers the nest to keep it warm. Unlike many other reptiles that leave their eggs, the alligator stays to keep them safe. When the babies start making noise, the mother knows they're ready to hatch. She may help by putting the eggs in her mouth and gently breaking the shells apart. Once the babies hatch, the mother gathers them up and puts them in the water. She stays with and protects her young for as long as two years.

Floods can cause tremendous damage. They can ruin houses, roads and buildings. Floods can take down trees and cause mudslides. It often leaves mud, sand and debris behind. It can take months to clean up after a flood.

Tennis is a racket sport that can be played individually against a single opponent (singles) or between two teams of two players each (doubles). Each player uses a tennis racket that is strung with cord to strike a hollow rubber ball covered with felt over or around a net and into the opponent's court.

On September 11th, you will notice the flag will fly at half staff. This means the flag will fly in the middle of the flag pole instead of the top. Some communities will have a moment of silence. This means that people will stop what they are doing, and think about the people who died for a little while. We also are thankful for community helpers, like police officers and firefighters, who help others every day.

Neil Armstrong may be the most famous astronaut of all, as the first man to step foot on the moon, and the speaker of the phrases “The Eagle has landed” and “That's one small step for man, one giant leap for mankind”.