题目内容

Go and ________ when the train is leaving．

[　　]

A．be sure

B．make sure

C．be sure of

D．be sure that

答案：B
解析：

make sure确信，确保。后跟句子结构。


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How Long Can People Live?

　　She took up skating at age 85, made her first movie appearance at age 114, and held a concert in the neighborhood on her 121st birthday．

　　Whe n it comes to long life, Jeanne Calment is the world’s recordholder．She lived to the ripe old age of 122．So is 122 the upper limit to the human life span(寿命)?If scientists come up with some sort of pill or diet that would slow aging, could we possibly make it to 150－or beyond?

　　Researchers don’t entirely agree on the answers．“Calment lived to 122, so it wouldn’t surprise me if someone alive today reaches 130 or 135,”says Jerry Shay at the University of Texas．

　　Steve Austad at the University of Texas agrees．“People can live much longer than we think,”he says．“Experts used to say that humans couldn’t live past 110．When Calment blew past that age, they raised the number to 120．So why can’t we go higher?”

　　The trouble with guessing how old people can live to be is that it’s all just guessing．“Anyone can make up a number,”says Rich Miller at the University of Michigan．“Usually the scientist who picks the highest number gets his name in Time magazine．”

　　Won’t new anti-aging techniques keep us alive for centuries?Any cure, says Miller, for aging would probably keep most of us kicking until about 120．Researchers are working on treatments that lengthen the life span of mice by 50 percent at most．So, if the average human life span is about 80 years, says Miller,“adding another 50 percent would get you to 120．”

　　So what can we conclude from this little disagreement among the researchers?That life span is flexible(有弹性的)，but there is a limit, says George Martin of the University of Washington．“We can get flies to live 50 percent longer,”he says．“But a fly’s never going to live 150 years．”

　　“Of course, if you became a new species(物种)，one that ages at a slower speed, that would be a different story,”he adds．

　　Does Martin really believe that humans could evolve(进化)their way to longer life?“It’s pretty cool to think about it,”he says with a smile．

(1)

What does the story of Jeanne Calment prove to us?

[　　]

A．

People can live to 122．

B．

Old people are creative．

C．

Women are sporty at 85．

D．

Women live longer than men．

(2)

According to Steve Austad at the University of Texas, ________．

[　　]

A．

the average human life span could be 110

B．

scientists cannot find ways to slow aging

C．

few people can expect to live to over 150

D．

researchers are not sure how long people can live

(3)

Who would agree that a scientist will become famous if he makes the wildest guess at longevity?

[　　]

A．

Jerry Shay．

B．

Steve Austad

C．

Rich Miller

D．

George Martin

(4)

What can we infer from the last three paragraphs?

[　　]

A．

Most of us could be good at sports even at 120．

B．

The average human life span cannot be doubled．

C．

Scientists believe mice are aging at a slower speed than before．

D．

New techniques could be used to change flies into a new species．

After sunset on our last day at the farm I walked out into the desert. In this, the first pleasant moment for a walk after long hot hours, I thought I was the only thing out of doors. Suddenly I stopped. Before me a rattlesnake lay fixed, its head not yet drawn back to strike but only turned a little to watch what I would do. Many snakes will run away at the sight of a man but this rattlesnake felt no necessity to get out of any-body's way. He held his ground in calm watch-fullness waiting for me to show my intentions. My first aim was to take no notice of him; I had never killed an animal if I was not forced to kill. But I remembered that there were children, dogs and horses at the farm as well as men and women with thin clothes on; my duty was to kill the snake. I went back to the farm and returned with a stick. The rattlesnake had not moved; he lay like a wire but more quickly than I could stride he shot into a bush and set up his rattling, warning me by this that I had made an unreasonable attack and attempted to take his life and that if I insisted he would have no choice but to take mine if he could. For a moment I listened to this terrifying sound and then I struck into the bush with my stick and, chop-ping about, dragged him out of the bush with his back broken. w.wHe struck once more at the stick but a moment later his neck was broken and he was soon dead althoughwww..com when I picked him up by the tail his mouth opened, proving that a dead snake may still bite. There was blood in his mouth and poison was dropping; it was not only a dis-gusting(令人作呕的) sight but a pitiful one too. I dropped the body into a green bush and, as I did so, I saw him in my imagination, crawling over the sands as he might have done if I had let him go.

49. At the sight of the author, the rattlesnake        .

A. shot into a bush

B. lay motionless but got ready to meet danger

C. drew itself up to strike

D. took no notice of his presence

50. The author had to kill the rattlesnake because       .

A. it stood in his way

B. it attempted to take his life

C. it presented a disgusting sight

D. its presence was a danger to the people and animals at the farm

51. Which of the following best describes the rattlesnake?

A. It attacked man without any reason.

B. It would not attack unless it was attacked.

C. It ran away at the sight of man.

D. It exposed itself to danger.

52. It is implied at the end of the passage that the author____.

A. regretted having killed the snake

B. was glad that he had killed the snake

C. felt a little sorry for the snake

D. could not help thinking about the dead snake

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