Almost all animals need to sleep to stay healthy. But sleeping can also be dangerous because other animals may hurt those who are sleeping. This leads to many different ways of sleeping that help them stay safe. Some of these ways may surprise you!

    Almost all bats sleep upside down. They hang from a branch of a tree or the ceiling of a cave. Up high, bats are safe from most other animals. If they are in danger, they just fly away.

    A dolphin sleeps with just half its brain at a time. It must stay awake to breathe and to watch for danger. Dolphin mothers and babies can go without sleep for as long as two months to stay safe.

    Some ducks sleep with just half their brains, too. These ducks often sleep in a line. The ducks at both ends help to keep the group safe. They keep one eye open to watch for danger. The ducks in the middle sleep deeply with both eyes closed.

    Seals breathe air, but that doesn't stop some of them from sleeping underwater. They hold their breath and dive deep to sleep for up to twenty minutes at a time. Sleeping deep underwater helps these seals stay safe from animals that hunt them near the surface.

    Horses often sleep standing up. Their legs lock in place so they don't fall over. If a horse is lying down, it needs a long time to get up. A horse can run from danger more quickly if it is already standing.

    A flamingo can sleep while standing on one leg. The standing leg locks so it stays straight. The other leg remains close to the flamingo's body. Its head rests on its back. A flamingo lives (and sleeps) near many other birds to stay safe.

    Some seabirds can sleep while they fly. These large birds spend most of their lives over the ocean. They are in danger on the water, but they are safe in the air. They fly for many hours without flapping（拍打）their wings. Sometimes they sleep while they are flying.

    Would you like to sleep how they sleep?

    In most parts of the world, many students help their schools make less pollution．They join environment clubs．In an environment club, people work together to make our environment clean．

    Here are some things students often do．

    No-garbage lunches．How many lunch bags do you throw away after lunch? Environment clubs ask students to bring their lunches in bags that can be used again．Every week they will choose the classes that make the least garbage and report them to the whole school．

    No-car day．On a no-car day, nobody comes to school in a car including the students and the teachers．Cars give pollution to us, so remember:

    Walk, jump, bike, or run!

    Use your legs! It's lots of fun!

    Turn off the water! Do you know that some toilets can waste twenty to forty cubic meters of water an hour? In a year, that would fill in a small river. In the environment clubs, students mend those broken toilets．

    We love our environment．Let's work together to make it better．

Using iPads to Make Learning Fun

    Paper, pencil, whiteboard, textbook are the tools you need if you want to go to school. But recently, you can add another one to the list: an iPad.

    Because the popular Apple tablet is not only useful for searching the Internet and watching videos, but it is also being used to make learning fun.

    Scientists now know that we learn better when we are enjoying ourselves, so recently software developers have made iPad applications(应用程序) that look like video games, but have strong educational content. One of the best examples of this new form of teaching application is Futaba, game in which up to four children try to recognize a spinning旋转的）object, and then identify what it is. The game can be used to teach English, math, foreign languages, or just about anything, and students love it. Teachers can even make their own questions. The important thing is that children enjoy the game, and don't even realize how much they are learning!

    So the next time you have to choose between making your child study or letting them play game, just remember——they could do both at the same time!

    Robots seem very new to most people. But they have a long history. The first one was made by a Greek inventor. You may have seen robots in some films. The robots in these films are stronger, faster and more clever than people in real life. Most robots are used in factories. They are used to do many dangerous, difficult or boring jobs. Some people can't look after themselves and move around. They need dogs to help them. These dogs are called guide dogs. Scientists are making robot dogs to help them. In the future, robot dogs might take the place of these guide dogs.

    Robots are also used in American hospitals. At one hospital, a robot takes meals from the kitchen to the sick people's rooms,   it never loses its way because it has a map of the hospital in its computer system.

    In the future, robots will work in space. But robots will never take the place of human beings, though they can help us in a lot of different ways.