When you watch TV programmes about wild animals，it is surprising to see how an antelope（羚羊）can run away from a strong lion.In the wild，everyone has its own way to protect itself.Even plants have their own ways to fight off enemies.
   Over millions of years，plants have developed their own defense system（防衛(wèi)系統(tǒng)）.Chemicals are often used by plants to survive.By making their leaves，flowers，roots and fruits poisonous（有毒） 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（量） of poison increases in the other leaves."It's like the injured leaves telephoning the others to fight together against the enemy，" he said.
   The tree also sends defense messages to neighbouring plants by giving out a special smell.Golden Wattle tees in the nearby 45 metres will get the message and produce more poison within 10 minutes.Now，if an enemy eats too many of the trees' leaves，he will die.
   Every kind of plant is good at producing a special set of chemicals.Herbivores（食草動(dòng)物） ，like rabbits，can safely eat the leaves of one tree，but they may be poisoned by its neighbor.
   In this way，plants have not only developed their own defense system，but also shared it with others.This makes it impossible for a single animal to destroy even a small area of forests.

（1）From the first two paragraphs，we can learn that

B

B

.
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

D

D

.
A.kill the animals with a special smell
B.tell other trees to come to protect it
C.warn other trees against the animals on the phone
D.send defense messages to the neighboring plants
（3）The passage is mainly about

C

C

.
A.the examples 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