题目内容：

When you watch TV programs about wild animals, it is surprising to see how an antelope can run away from a lion. In the wilderness, everyone has his own way to protect  himself. Even plants have their own ways of fighting off enemies.

Over millions of years of evolution, plants have developed their own  defence system(防御系统). Chemicals are wildly used for survival（生存）. By making their leaves, flowers, roots and fruits distasteful or poisonous(有毒的) to enemies, plants can fight back.

One such plant is the Golden Wattle tree. The British scientist David Cameron has found when an animal eats the tree’s leaves, the amount of poison increases in the other leaves. “It’s like the damaged leaves telephoning the others telling them to fight together against the enemy, ” he said.

The tree also sends defence messages to neighboring plants by giving out a special smell. Golden Wattle trees in the surrounding 45 meters will get the message and produce more poison within 10 minutes. Now, if an enemy eats too many of the trees’ leaves, it will die.

Every species of plant or tree is good at the production of a particular set of chemicals. A herbivore that can safely eat the leaves of one tree may be poisoned by its neighbor.

In this way, plants have developed not only individual defence system, but also shared it with others. This makes it impossible for a single animal to destroy even a small area of forest.

1.From the first 2 paragraphs,we can learn that________

A. plants can do nothing against their enemies.

B. Chemicals are quite useful for plants to survive.

C. An antelope can always run away from a strong lion.

D. Leaves,roots,flowers and fruits of plants are poisonous.

2.If animals eat one Golden Wattle tree’s leaves,the tree can________

A. kill the animals with special smell.

B. tell other trees to come to protect it.

C. warn other trees against the animals on the phone.

D. send defence messages to the neighboring plants.

3.The word “herbivore”  in the 5th paragraph probably means animals which ____.

A. produce poison

B. live on small animals

C. like to eat rabbits

D. feed on plants or grass

4.The last paragraph of the passsage suggests that this kind of defence system is_____

A. bad for animals

B. good for forests

C. helpful to some animals

D. harmful to forests.

5.The passage is mainly about______

A. the example of protecting forests

B. the balance between animals and plants

C. the ways of plants fighting against enemies

D. the relationship between lions and antelopes