问题 单项选择题 A1/A2型题

关于汞中毒以下说法正确的是()。

A.汞为灰白色质软的重金属

B.可溶于水

C.人类在正常的生活中接触不到汞及其化合物

D.尿汞阳性是诊断急性汞中毒早期的重要指标

E.汞的无机化合物主要是通过消化道侵入人体

答案

参考答案:E

解析:汞为银白色的液态金属,常温中即有蒸发。汞中毒以慢性为多见,主要发生在生产活动中,长期吸入汞蒸气和汞化合物粉尘所致。以精神-神经异常、齿龈炎、震颤为主要症状。大剂量汞蒸气吸入或汞化合物摄入即发生急性汞中毒。对汞过敏者,即使局部涂抹汞油基质制剂,亦可发生中毒。急性汞中毒主要由口服升汞等汞化合物引起,慢性汞中毒常为职业性吸入汞蒸气所致。

阅读理解

Every pet owner loves his pet. There is no argument here.

But when we asked our readers whether they would clone(克隆) their beloved animals, the answers were split almost down the middle. Of the 228 readers who answered it, 108 would clone, 111 would not and nine weighed each side without offering an opinion.

Clearly, from readers’ response, this is an issue that reaches deeply into both the joy and final sadness of owning a pet. It speaks, as well, to people’s widely differing expectations over the developing scientific procedure.

Most of the respondents (被调查的人) who liked the idea strongly believed it would produce at least a close copy of the original; many felt the process would actually return an exact copy. Those on the other side, however, held little hope a clone could never truly recreate a pet, many simply didn’t wish to go against the natural law of life and death.

Both sides expressed equal love for their animals. More than a few respondents owned “the best dog/cat in the world”. They thought of their pets as their “best friend”, “a member of the family,” “the light of my life.” They told moving stories of pets’ heroism(英勇精神), cleverness and selfless devotion.

“People become very close to their animals, and the loss can be just as hard to bear as when a friend or family member dies,” says Gary Kowalski, author of Goodbye, Friend: Healing Wisdom for Anyone Who Has Ever Lost a Pet. “For me, cloning feels like an attempt to turn death away…It’s understandable. Death is always painful. It’s difficult to deal with. It’s hard to accept.”

  But would cloning reduce the blow? This question seemed to be at the heart of this problem.

71. So far as the cloning of pets is concerned, a recent survey shows that, of all pet owners, __________.

A. a lot more of them are for it  

B. a lot more of them are against it

C. very few of them are willing to tell their opinions

D. about half of them are for it and the other half against it

72. While talking about the respondents from the readers, the underlined expression “final sadness of owning a pet” refers to ___________.

A. the death of one’s pet   

B. the high cost of owning a pet

C. the troubles one has to deal with in keeping a pet

D. the dangers involved in the cloning of a pet

73. In spite of(尽管) their differences on the problem of cloning, it seems that ________.

A. all pet owners try to go against the natural law of life and death

B. all pet owners love their pets very much

C. people who support cloning love their pets more

D. people who dislike cloning love their pets more

74. From what Gary Kowalski says, we can know that he _________.

A. has never thought about the problem of cloning

B. is going to write another book on pets

C. support the idea of cloning pets

D. is all against the cloning of pets

75. What is the key question at the heart of the problem of cloning pets?

A. Can cloning make one suffers less pain when a pet dies?

B. Can pet owners afford the cost of cloning?

C. Does cloning go against the law of nature?

D. Can cloning really produce an exact copy of one’s pet?

单项选择题