DNA是主要的遗传物质。

NSFNET采用的是一种 【5】 结构，分为主干网、地区网和校园网。

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Tony: These days, the word "clone" has been seen very often in the newspapers. Do you know

          its meaning?

Lana: I read a report. It said that Dr. Ian Wilmut successfully cloned a lamb named Dolly from

          a grown-up sheep. So people call him the "father" of Dolly.

Tony: In fact, the word "clone" means to produce the "same" animal by taking cells from a

          grown-up one. I think, if we know how to do cloning, we need only to keep a small number

         of sheep, cows or horses.

Lana: What's more, these days some people even want to clone humans. They have asked: Can

          we clone ourselves?

Tony: It seems interesting. But do you think it possible to do that?

Lana: No, impossible! First, I think we cannot clone a dead person, because the cells in his body

          are dead already.

Tony: Then can we clone a living person?

Lana: Again no! You might clone yourself one after another, but it is only a copy, not a real you.

          It is only something, not a "human".

Tony: Well, you mean that it is not a real human.

Lana: True enough! I think Dr. Wilmut would most like to make better animals, and it has nothing

          to do with human cloning.

1. The word "clone" means ___________.

A. to give birth to a new life  

B. to make a new thing according to the sample

C. to make a new animal      

D. to make a new living thing by taking cells from an old one

2. Dolly was the name of _________.

A. the father of a sheep            

B. a famous scientist

C. a sheep that was cloned          

D. a grown-up sheep

3. Lana says Dr. Ian Wilmut is the "father" of Dolly. Here, she means _______.

A. Dr. Ian Wilmut gave Dolly a new life

B. Dr. Ian Wilmut was the first man to clone a sheep in his lab

C. Dr. Ian Wilmut takes care of Dolly like a father

D. Dr. Ian Wilmut has a daughter whose name is Dolly

4. What are Tony and Lana talking about? They are talking about _________.

A. a newspaper    

B. sheep      

C. Cloning technique    

D. humans

5. According to the text, which of the following is TRUE?

A. Scientists have successfully cloned humans.

B. Dr. Wilmut likes to do human cloning.

C. Cloned animals are better than grown-up ones.

D. Lana thinks humans shouldn't be cloned.

使用美沙酮对海洛因依赖患者进行替代治疗，应注意()

A．一般在14～21天内将美沙酮逐渐减少，最后停用

B．逐日减量，只减不加，限时减完

C．首日使用剂量可通过观察瞳孔、脉搏、血压及其他戒断症状来判定

D．一旦美沙酮减完后即可让病人出院

E．减量过程可以先快后慢

根据《电力安全生产监管办法》，各电力企业对本单位的安全生产全面负责。其主要行政负责人是安全生产第一责任人。

日本人出席葬礼时穿（）色礼服，日本人的墓地大多在（）。