【正文】 ation was not successfulC. Jason was made blind in the car accident D. Jason knew how Sam helped him before Sam died50. From the story, we can conclude(得出結(jié)論) that __________.A. Sam played a joke on Jason B. Sam always told lies to his friendsC. Sam thought friendship was important D. Sam regretted doing the operation in the end8：單選When you watch TV programs about wild animals, it is surprising to see how an antelope (羚羊) can run away from a strong lion. In the wilderness, everyone has his own way to protect himself. 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 fantastically used by plants to survive (幸存). 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. The British scientist David Cameron has found when an animal eats the tree’s leaves, the amount (數(shù)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 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, he will die.Every kind of plant or tree is good at producing a special set of chemicals. Herbivores, 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 forest. 51. 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 poisonous52. If animals eat one Golden Wattle tree’s leaves, the tree can________.A. kill the animals with a special smell B. tell other trees to e to protect itC. warn other trees against the animals on the phoneD. send defense messages to the neighboring plants53. The underlined word “herbivores” in the 5th paragraph probably means animals which _____.A．produce poison B．live on small animalsC．like to eat rabbits D．feed on plants or grass54. The last paragraph of the passage suggests that this kind of defense system is ________.A．bad for animals B．good for forestsC．helpful to some animals D．harmful to forests55. The passage is mainly about __________. A．the examples of protecting forestsB．the balance between animals and plants C．the ways of plants fighting against enemies D．the relationship between lions and antelopes46. B 47. D 48. A 49. C 50. C51. B 52. D 53. D 54. B 55. C8