WhenyouwatchTVprogramsaboutwildanimals,itissurprisingto...

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When you watch TV programs about wild animals, it is surprising to see how an antelope can escape a lion’s attack. In the wilderness, everyone has a stunt(绝招). Even plants have their own ways of fighting off enemies.

Over millions of years of evolution(进化), plants have developed a unique defence system(防卫系统). Chemicals are widely used for survival. By making their leaves, flowers, roots and fruits poisonous (有毒的)to enemies, plants can fight back.

One such plant is the Golden Wattle tree, British scientist David Caneron has found when an animal eats the tree’s leaves, the amount(数量)of poison increase in the other leaves. “It’s like the injured 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 nearby 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 producing a special 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 their own defence system, but also shared with others. This makes it impossible for a single animal to destroy even a small area of forest.

43. Which of the following can be the best title of the passage?

A. Plants Fight Back With Poisons

B. Plants Can Kill Animals

C. Animals and Plants.

D. Lions and Antelopes

44. According to the study, if one Golden Wattle tree is attacked by animals, it can ________.

A. tell other trees to protect it

B. produce more poison within 10 minutes

C. sent defence messages to the neighboring plants

D. kill the animals with its leaves

45. In this passage the underlined word “herbivore” probably means animals which .

A. live on both animals and plants