2. 外语
  3. We all scream for water【C1】______thirsty. But do you know in very hot, dry weather, plants also make faint sounds —【C2】______the

We all scream for water【C1】______thirsty. But do you know in very hot, dry weather, plants also make faint sounds —【C2】______the

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问题     We all scream for water【C1】______thirsty. But do you know in very hot, dry weather, plants also make faint sounds —【C2】______they are crying out for help?
    You see, in a plant’s stem, there are hundreds of water pipes that bring water and minerals from the soil【C3】______up to the leaves.【C4】______the ground turns dry, it becomes harder and harder for the plants to do this. In【C5】______droughts, plants have to fight to【C6】______any water available. Scientist Robert Winter has found out that when it is really bad, their water pipes【C7】______from the【C8】______like rubber bands. When that happens, the whole plant vibrates a little. The snapping pipes make noises【C9】______than a whisper. Robert knows that healthy, 【C10】______plants are quiet. He also knows that many insects prefer attacking【C11】______plants【C12】______healthy plants.
    How do the insects know which are healthy plants and which are not? Robert thinks that the insects may listen for the plants that cry. And then they【C13】______buzz in to kill. To【C14】______his theory, Robert is using a【C15】______that can【C16】______plant cries. He attaches it【C17】______a quiet, healthy plant so the plant sounds thirsty. Then he watches the insects to see if they attack more often than usual. If he is right, scientists could use the insects’ ability【C18】______them. They could build traps that imitate crying plants,【C19】______when the insects buzz in to eat, they won’t buzz【C20】______
【C14】
选项 A、be tested
B、testing
C、test
D、be testing
答案C
解析 语法辨析题。此处的to为动词不定式，相当于in order to，因此to后需用动词原形。
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