题目内容：

Plants are very important living things．Life could not go on if there were no plants．This is because plants can make food from air, water and sunlight．Animals and men can’t make food from air, water and sunlight．Animals get their food by eating plants and other animals．Therefore, animals and men need plants in order to live．This is the reason why we find so many plants around us.

If you look carefully at the plants around you, you will find that there are many kinds of plants．Some plants are large while others are small．Most plants are green.

Some plants have many small leaves．Others have only a few．There are many kinds of leaves．Leaves are of different shapes and colors.

Leaves are also different in other ways．Some leaves have long thin parts at the end, we call them leaf stalks, some have short leaf stalks, others even have no leaf stalks．The leaf edges are also different．Some leaves have smooth(平滑) edges．Some have a wave-shaped edges．Others have edges like the teeth of a saw(锯子).

根据短文内容，选择最佳选项。

1.Which of the following shows the right relation(关系) according to the first paragraph?

A. air—water—sunlight       plants      food

B. air—water—sunlight      men        food

C. air—water—sunlight       animals      food

D. air—water—sunlight        living things   food

2.We know from the passage that _________.

A. all leaves have leaf stal

B. all leaves have smooth edges

C. plants are different in shapes but have the same color

D. leaves are different in shapes and colors

3.The underlined words “leaf stalks” in the last paragraph means______.

A. 叶边    B. 叶纹    C. 叶柄    D. 叶尖

4.The main idea of the passage is ________.

A. how plants help men and animals

B. plants are important and they are quite different

C. plants are more important than air, water and sunlight

D. why we find so many plants and around us