The population of the Earth is growing faster. It is important that we look after the Earth. We need it! The Earth gives us a lot of things. We also give the Earth a lot, but some of the things are not good.

   In nature, when something dies, other animals and plants get food from it. Every animal or plant gives food for other animals or plants. However, animals can't get food from many of the things that we "give"the Earth. Animals and plants can't eat metal, plastic and glass. These things will stay in the ground for many, many years.
   Some rubbish is very dangerous for plants and animals. In some places, many animals live together. One animal makes food for many more animals. If we put rubbish and chemicals in the water, the plankton(浮游生物) can die. If there isn't any plankton, many animals have nothing to eat.
   So what can we do? Don't leave any rubbish in the countryside! Don't make so much rubbish!

    Mother's Day is a holiday for mothers. It is celebrated in the United States, England, India and some other countries. In a short time, it becomes widely celebrated Mother's Day falls on the second Sunday in May. On that day many people send gifts of love to their mothers. Those whose mothers are still living often wear a pink or red rose or carnation(康乃馨), while those whose mothers are dead wear a white one.

    The idea of a day for mothers was first given by Miss Anna Jarvis of Philadelphia As a result of her hard work, the celebration of the first American Mother's Day was held in Philadelphia on May 10, 1908. Soon the holiday became popular all over the country and around the world.

    In China, people do the same on the day for mothers, And, in some cities, people sometimes ask a song to be broadcasted for his or her mother only. This might cost a little money for some of them, but, as it is said, "Love is invaluable."

    On May 8, 1999, just the day before the Mother's Day that year, a Chinese mother, a heroic(英雄的) mother was killed in criminal bombing(罪悉轰炸)in Yugoslavia(南斯拉夫). Her name is Shao Yunhuan, a reporter who wrote lots of articles(文章)for Chinese newspapers. All the Chinese will remember her forever.

Anna's coat is too small. She goes shopping with her mother on Sunday. She wants to buy a new coat. They go into a clothing shop first (首先). Anna finds a green coat in the clothing shop. She likes it very much. She tries it on, but it's too small for her. She wants a big one, but the big one is not green. She isn't happy.

Then she wants to go to another (另一个) shop to have a look. Then they find a new shop. The shop is big. There they see many kinds of coats in different colors and sizes (尺码). Anna tries on a green one. It looks nice on her. Anna is very happy. She takes it for fifty yuan. 

①In most places in the world today, it is easy to find healthy food. With supermarkets, buying healthy food like fresh fruits, vegetables, fish, and meat is easy and convenient（便利的）. However, it is also easy to find unhealthy food today. Supermarkets and other stores sell good food, but they also sell frozen foods and junk food like chips, candy, and cookies. A lot of food today has chemicals（化学药品）. Research has shown that many of these chemicals are bad for our health. So did people in the past eat healthier than we do today?

②A century ago, people didn't eat junk food or frozen food. Instead, they ate natural foods without chemicals. On the other hand, their natural foods were not always as good as food today. In the past, meat often came from sick animals. It's not healthy to eat meat from a sick animal. In most places today, laws make sure that food is safe.

③In most countries today, we can buy a variety（各种）of foods. We can buy oranges in the winter and apples in the summer. Healthy fruits and vegetables are available（可获得的）at any time of year. These foods come from all over the world. In the past, this kind of variety was not possible. People could eat certain foods only in certain seasons.

④We also eat much more meat, sugar, fattening foods, and chemicals today than people did a century ago. Studies show that these things can cause（引起）heart disease（疾病）and a variety of other health problems. However, people live much longer now. Today, the average（平均）person lives for 70 to 80 years. However,100 years ago, the average person lived for only about 50 years. People live longer because we have better medicine now. But people also have longer lives because healthy food is usually available.

⑤So ____? Yes and no. People in the past did eat more natural food than we do now. But, in some ways, we also eat better today. We can eat healthier today than people did in the past. We just have to choose to eat good foods.

Purple, green, orange, red. animals have a lot of beautiful and different colors. These colors are important to them. Some animals use the colors to make their enemies (敌人) afraid. And sometimes their enemies can not see them clearly because their colors are like some other things. Other animals use the colors to find partners. But how do animals have their colors?

Food gives them colors

Some animals get pigments (色素) from their food. For example, flamingos eat a lot of shrimp or algae. These things have a red-orange pigment. The pigment gives flamingos a pink color. The more they eat, the pinker they get.

Body gives them colors

Animals' body parts, like feathers, scales (鳞片), hair and skin, have special structures. They reflect (反射) light to make animals colorful. This is called structural colors. For example, blue morpho butterflies (蓝闪蝶) have beautiful scales on their wings. This gives them a bright blue color.

Did you know?

Structural colors don't fade (褪色). People use the idea to make special clothes and paints.