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英语科普文 英语科普文阅读方法与实例
一、考点描述 科普类文 bitter or cause an unpleasant reaction. Some plants may fight against an attack by increasing the production of these chemicals. When a caterpillar (毛虫) bites a tobacco leaf，the leaf produces a chemical messenger. This messenger sends to the roots the information to produce more nicotine. The higher levels of nicotine discourage the caterpillar.
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Many plants depend on both physical and chemical defenses. A certain plant in China，for instance，has prickly (多刺的) leaves，and each prickle contains poisonous venom (毒液).A single experience with this kind of plant will teach an animal to stay away from it in the future.
68. The holly plant has more spines on the lower leaves because most animals_____________.
A. are not tall enough B. like the lower leaves only
C. are not clever enough D. can get the lower leaves easily
69. To defend themselves，oak trees use___________.
A. chemical means B. physical means
C. bitter chemicals D. sandy materials
70. How does tobacco protect itself against an attack from a caterpillar?
A. Its leaves fight against the attack by physical means.
B. Its roots send a messenger to discourage the caterpillar.
C. Its roots increase the production of nicotine when it is attacked.
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D. Its leaves produce poisonous sand to drive the caterpillar away.
71. What would be the best title for this passage?
A. Plants and Animals B. How Plants Defend Themselves
C. Attacks and Defenses D. How Animals Eat Plant Leaves
【答案与解析】本文主要介绍一些植物是如何通过物理和化学的方式保护自己不受外界侵害的。
68. D。事实细节题。根据第2段最后一句...the lower leaves are easier for most animals to reach可知答案。
69. B。推理判断题。根据第3段中的...oak tree，have thick and hard leaves that are difficult for