阅读理解。
All living things on the earth need other living things to live. Nothing lives alone. Most
animals must live in a group, and even a plant grows close together with others of the
same kind. Sometimes one living thing kills another, one eats and the other is eaten. Each
kind of life eats another kind of life in order to live, and together they form a food chain.
Some food chains become broken up if one of the links disappears.
All life need sunlight to live on. 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. Some animals feed directly on plants, others eat smaller animals. Meat-eating
animals are only eating plants directly.
What about human beings? We are members of many food chains. We eat wheat, rice,
vegetables. fruits and so on. We also eat meat and drink mild. But men often break up the
food chains. They kill wild animals. They also make rivers, lakes and seas dirty. When these
rivers, lakes and seas are polluted, the fish in them can not be eaten. If men eat the fish, they
will get diseases.
Each form of life is linked to all others. Breaking the lines puts all life in danger.
1. How does every living thing on the earth live? [ ]
A. Each plant can live alone.
B. Each animal can live alone.
C. If living things want to live, they must kill each other.
D. Every living thing on the earth cannot live without others.
2. Which living things can use the sun's energy directly? [ ]
A. Animals.
B. Plants.
C. Both A and
B. D.All living things.
3. What do plants make food from?
They make food from _____. [ ]
A. sunlight, water and things in the soil and air
B. water, sunlight and things in the soil
C. water and things in the soil and air
D. water, sunlight and things in the soil
4. Who often break up the food chain? [ ]
A. Human beings.
B. Animals.
C. Plants and animals.
D. Men and wild animals.
5. Which of the following do you think is the best title for this passage?[ ]
A. Animals.
B. Plants.
C. Food chains.
D. Living things.
有机物C9H8O发生如下反应：
，则C9H8O的结构简式为_____________ 。