题目内容
All living things on the earth need other living things to live. Nothing lives alone 1.. Each kind of life eats another kind of life in order to live, and together they form a food chain. Some food chains are simple, while others are not. But all food chains begin with the sun, and all food chains become broken up if one of them disappears.
2.. But only plants can use sunlight directly. Plants are “factories”. They make food from sunlight, water and things in the soil and air. Plants feed all other living things.
Animals can only use the sun’s energy after it has been changed into food by plants. 3.. Meat-eating animals are only eating plants indirectly.
What about our human beings? We are members of many food chains. We eat wheat, rice, vegetables, fruits and so on. We watched a display show. It was exciting. We also eat meat and drink milk. But men often break up the food chain, 4.. They also make rivers, lakes and seas dirty. When these rivers, lakes and seas are polluted, the fish in them cannot be eaten. If men eat the fish, they will get strange diseases.
Each form of life is linked to all others. Breaking the links puts all life in danger.
A. They burn forests and kill wild animals.
B. Food chains should not be broken up.
C. Sometimes one living thing kills another, one eats and the other is eaten.
D. All life needs sunlight to live on.
E. Some animals feed directly on plants and others eat smaller animals.
