58. When "water pipes" snap, the whole plant_________.

A. keeps quiet          B. vibrates a little

C. gets well          D. makes very loud sounds

57. When plants can________,  their "water pipes" snap.

A. grow well         B. get no sunlight

C. have enough water        D. get no water

Robert knows that healthy, well-watered plants are quiet. He also knows that many insects (昆虫) prefer attacking dry plants rather than healthy plants. How do the insects know which are healthy plants and which are not? Robert thinks that the insects may hear the plants crying and then they may come to kill. . 56. There are many "water pipes"_________.

A. in a plant's stem

B. in a plant's peel(果皮)

C. in a plant's bark(树皮)

D. in the earth

55. Which of the following is right?

A. The journey lasted 100 days.

B. Each boat was different.

C. It was hard to get to the end of the race.

D. Debra Veal wanted to leave her boat as soon as the race ended.

(B)

We all cry for water when we are thirsty. But do you know,  in very hot,  dry weather,  plants also make very low sounds ― as if they are crying out for help?

You see,  in a plant's stem(茎) there are several hundred "water pipes(管道)" that bring water from soil all the way up to the leaves. When the ground turns dry,  it becomes harder and harder for plants to do this.

In very hot days,  plants have to get any water that it can.

Scientist Robert Winter has found out that when plants can get no water, their "water pipes" snap(发出断裂声) . When that happens,  the whole plant vibrates( 振动 ) a little. The snapping pipes make noises ten thousand times more quiet than a whisper(低语).

54. "this lady" refers to(指的是)_________.

A. her mother       B. herself

C. her boat       D. the journey

53. Debra Veal's husband gave up because_________.

A. it was a dangerous journey

B. he had to look after their child

C. there was no food for the journey

D. he was fed up with the journey

52. The race started_________.

A. on October 7^th , 2001 from Tenerife

B. on October 7th , 2001 from Barbados

Con January 26^th , 2002 from Tenerife

D. on January 26^th , 2002 from Barbados

51. _________boats took part in the race across the Atlantic.

A. 14       B. 36        G. 2, 001         D. 3, 360

49. A. nobody         B. somebody          C. everybody