There are many kinds of animals that live in the forest, such as mice, rabbits, squirrels, bears.

    Animals in the forest depend on（依靠）one another for food. Many small forest animals, such as mice, eat green plants for food, and then larger animals eat them. This is called food chain. A food chain begins with the sun. The green plants in the forest use the sun's energy to make food for themselves. It's called photosynthesis(光合作用). Mice eat flowers and seeds that forest plants produce(生产).The mice get their energy from the plants, and the mice become food for a larger animal, such as the hunting hawk. So the energy from the sun passes from the plants to the mice to the hawk. A break（中断）in any part of this food chain means some animals may not have enough food to eat.

    If you put your history notes under your pillow (枕头) and sleep on them the night before an exam, will you do any better on the test? Most of us have hoped this might help. However, _______ can't go through the pillow into your brain. But that doesn't mean you can't learn while you sleep.  

    Scientists aren't exactly sure how it works, but they have discovered that the brain can learn things during sleeping hours.

    In one experiment(实验), researchers gave German speakers some Dutch words to learn. Then, they divided them into three groups. The researchers played Dutch words for people in Group 1 while they slept, without telling these German speakers what they were doing. The sound was low so it didn't wake them up, and only the newly introduced words were used.

    Another group listened to the same words while they were awake. The researchers found the people in Group 1 were better able to identify(确认) and translate the words later. This was true only for the words that were played while they slept. The third group listened to words while they walked. The walkers did not have the same success remembering the words as the sleeping group.

    The researchers later found that people had more slow-wave(慢波的) brain activity throughout the night. They said that more slow waves made people have better memory for the new words.

                                B     

    Hippos(河马) live in Africa(非洲). They are one of the world's largest land animals. Here are some interesting facts about them.

●Where are hippos born?

    Hippos often give birth in the water. The hippo babies get out of water right after birth to take their first breath.

●How quickly do hippos grow up?

    Hippo babies nurse both under water and on land for a year. Then they stop taking their mothers' milk but they are still with their mothers until they are eight years old. Then they move out.

●What do hippos love?

    Hippos love water and they spend most of the day in it to stay cool. The Hippo can breathe, see and hear when its body is under water because its nose, eyes and ears are on the top of its head.

●Do hippos swim better than people?

    Yes, they are great swimmers and they can hold(屏住) their breath for five minutes. Hippos can even walk under water along the bottom(水底) of rivers and lakes.

    A hundred years ago, most people thought that human beings would never fly. And the idea of flying seemed crazy and dangerous. But as a new world full of new inventions（发明物）came, everyone was trying to break the old thoughts. So many inventors, like Orville and Wilbur Wright, tried to make a flying thing.

    Most plane inventors at that time were impulsive. They would think of an idea, make a plane as quickly as they could, and then try to fly it as soon as possible. All of them had the same result they took their planes home and they had no idea why they didn't work.

    However, the Wright brothers were much smarter inventors. They tested their ideas in smaller or safer ones before making a real plane. For example, the Wright brothers made a wind tunnel(隧道)to compare(比较)wing shape ideas. They also flew lots of kites to test their ideas. They studied the way birds fly through the air and tried to learn something from it when making their models. Finally, the Wright brothers felt they were ready to test their planes, but they needed to find the right place. They knew the right place to test their planes after writing to the US Weather Bureau for help. At last on December 17th, 1903, Orville and Wilbur tested the plane and they made it.

    The plane flied for twelve seconds and it traveled just 120 feet, but Orville and Wilbur were very happy. Their plane really worked! By the end of the day, both brothers had great successful flights(飞行), with Wilbur having a record of 852 feet in 59 seconds.

    Developing healthy eating habits starts from childhood, therefore it is important for parents to teach and provide children with a healthy diet.

    DPHSS administrator of the Bureau of Nutrition Services, Charlie Morris said, "A healthy diet for a child always includes a lot of fruits and vegetables in the diet limiting the amount of simple sugars in the diet and high fat food and highly processed* food." This means staying away as much as possible from food such as chips, cookies, candies and sugary drinks, because all children need to have meals and the meals should be a well-balanced diet.

    Community nutritionist* Thelma Romoso said, "The fruit, the vegetable, the grain, the protein, and also the milk, the diary product are all necessary in the diet for a child. Among them, the fruit and the vegetable should come first. It's easy for a mother to go into the two plus three concept* of fruits and vegetables or five a day." This concept means that there are at least two servings* of fruits a day, three servings of vegetables a day which can be served for lunch and dinner.

    Morris also said that the child's hunger level influences how much is eaten and the parent controls what and when the meal is offered, saying, "Mom needs to make sure that the food offered is good food for the child to eat and she also needs to consider how active they are through the day. Snacks* are not a bad thing, so the mom should offer good kinds of snacks as well."

    When it comes to preparing your child's lunch and snacks for school, make sure to keep in mind that the food you provide should not only provide enough energy but also be healthy such as fresh fruits, and whole grain bread. But parents must be sure to remember that a good healthy diet must be balanced with physical activity, that is to say, it is important that children get outside and run around and play and get activity besides eating a good diet.