If music makes you smarter and exercise helps you to think, surely exercising to music can turn you into an intelligent(聪明的) person.

    A team of scientists from Ohio State University did tests on 33 volunteers who were getting better from heart problems following operation(手术). They found that people who exercised while listening to "The Four Seasons" did much better on language ability tests than without music.

    "Facts suggest that exercise improve the learning ability of people with heart problems," said the scientist Charles Emery, who led the study. "And listening to music is thought to enhance understanding. We just wanted to put the two results together." he added.

    The volunteers said they felt better after exercising with or without the music. But their improvement on the test doubled after listening to music during exercise. Scientists have shown it is true that music can be good for health. It helps cut down stress, sadness and nervousness. And it also wakes up the body and improves memory and thoughts.

    In medical fields, music is used widely for patients who have had headaches before and after operation. "The Four Seasons" was used because of its soft tempo(节拍) and better results in earlier research.

    "Exercise seems to cause better changes in the nervous system and these changes may have a direct result on learning ability." Emery said. Scientists have been studying the result of music on understanding since the early 1950s. By 1990, scientists were using Mozart's music to help children with speech disorders. Mozart was chosen because his music is not overexciting. A study showed students who listened to Mozart scored higher marks in an intelligence test. With important exams coming, your parents will not probably allow you to listen to music. But perhaps now you have good reasons to argue with them.

    One day, you open the fridge and find some moldy (发霉的)food. But before you can throw it away, your mother stops you. She doesn't want to waste food. She cuts off the moldy part and eats the rest. Is it safe to do this?

    Mold (霉菌)can grow on almost all kinds of food. Mold is usually green, white, black or grey. Mold makes food soft and changes its color. Moldy food tastes quite bad一一and it's not safe to eat.

    If you find mold in soft food, just throw it away. Soft food, such as bread, tomatoes or hot dogs, usually contains water. This allows mold to easily grow below its surface. Bacteria (细菌)can also grow along with it.

    But it's easy to remove mold from hard food. The mold can't grow very deeply inside this kind of food. According to the BBC, you should cut about 2.5 cm around and below the mold to remove it. It's OK to cut the moldy parts out of hard food and eat the rest. But if the food is completely covered with mold, you should still throw it away.

    Most kinds of mold are bad for us. But some kinds of mold can be used to make food. For example, penicillium (青霉菌)can be used to make many types of cheeses, such as blue cheese. These cheeses are safe to eat--and they're quite delicious as well.

How to make ice-cream in a bag

    What you need:

    I spoon of sugar, 1/2 cup of "half and half" (牛奶和奶油的混合物)，1/4 spoon of vanilla extract(香草精), d add 1 spoon of sugar, 1/2 cup of "half and half" and 1/4 spoon of vanilla extract to the small bag.

    Next, add three glasses of ice 10 the big bag. You can add more or less just to make sure that the small bag will be covered by ice.

    Then, pour about 1/2 cup of salt into the big bag. The salt helps the ice get cold so you can add more if necessary.

    When it's ready, place the small bag in the big bag and seal tightly(系紧). You need to shake the bag for about five minutes.

    Finally, take the small bag out. Be careful not to open it. Wipe off(擦去) any salt on the bag. Now open the bag. You can enjoy your ice cream. You can finish all of the work in less than ten minutes.

    What is the sky? How high is it? What color is it? What birds can live above it? These questions are difficult to answer, aren't they? In fact, the sky has no color. Then why does the sky look blue?

    We know that there is air around the world. When planes fly, they need air to lift their wings. Planes can't fly very high. That is because the air gets thinner when they go higher. The same will happen to us if we go high enough. If we go up about 1,200 kilometers from the earth, we'll find no air there. Some birds can fly into the sky as high as a plane, but they cannot fly or live without air.

    Looking up above us, you will see the blue sky with white clouds. It is usually light blue. The color would be bluer when you see on the top of a high mountain. And you will see fewer clouds in the sky between you and the sun. Sometimes the sky doesn't look blue. When the sun rises and falls, you will see red, orange and other colors in the sky, such are the most beautiful moments of the day.

    Who can see the colors of the sky high above the earth? The astronauts! They can see those beautiful colors of the sky from the outer space. However, before flying into the outer space, they sit in a spaceship high above the earth and there is no air at all. The sky would be that dark and its color would be black.

    Now you may understand that we see colors because the air scatters (使散射) the sunlight. Light travels through the air. Without air there would be no colors.

    Laughter is natural for people. We start to laugh at about four months of age. We start to laugh even 1 we start to speak.

    Laughter connects us with others. We laugh more when we are with other people. It's difficult to pretend to laugh. Laughter is 2. When people pretend to laugh, most people know it's not real.

    When do people laugh?

    Only 10 to 20 percent of laughter is about something 3. Most laughter is about being friendly with other people. Most laughter says, "I don't want to 4 with you. I want to be friendly with you." This kind of laughter brings people together.

    We often laugh when we feel nervous. In movies, there is often a joke at an exciting moment when everyone feels nervous. It is usually a(n) 5 joke, but we laugh a lot. Our laughter helps us 6.

    Why doesn't everyone laugh at the same joke?

    Not everyone has the same sense of 7. Some people think a joke is funny, but other people don't think so. People have different ideas about what is funny.

    Our idea of what is funny changes with 8. For young children, the world is new. They are interested in many things, so they laugh 9. Teenagers often laugh to protect themselves. Adults laugh at themselves and other people with similar problems. They laugh at things that give them stress. Our 10 for laughter change gradually.