问题 单项选择题

肾性贫血最主要原因是下列哪项

A.红细胞寿命缩短

B.消化道失血

C.蛋白质摄入量不足

D.铁及叶酸摄入不足

E.促红细胞生成素合成不足

答案

参考答案:E

阅读理解

阅读理解。

     Not long ago, Richard Denniston found himself suffering the same pain that millions of other pet owners

have faced. His little dog had a brain tumor (肿块) and would soon die. Like others who faced the problem

before him, Denniston just wanted to end his pet's suffering.

    However, he took one step further.

    Denniston, an expert who studies animals collected a tiny skin sample (小块皮肤样本) from the dog and

took it to his laboratory at Louisiana State University. Denniston started a new technology. Denniston's

company will save pet's DNA for US $500, plus a monthly storage fee (保存费) of US $10, until cloning

becomes a reality (现实).

     "It could happen soon if everything went on well," says Mark Westhusin, a professor leading a dog

cloning team. Most experts put successful dog cloning a year to five years down the road. The cost may

be expensive at first, but it would drop at last.

     Since Dolly the Sheep was first cloned in 1996, cattle, goats, mice and monkeys have been cloned in labs.

Pets are likely to be next.

1. After his pet died, Richard Denniston ______.

A. did something more than the ordinary pet owners

B. did as other pet owners

C. did nothing but feel very sad

D. could not help feeling lonely without his dear pet

2. Richard Denniston's company will ______.

A. work on DNA

B. clone dogs

C. clone sheep

D. clone human

3. If you put your pet's DNA in Richard Denniston's company for six months, you'll have to pay ______.

A. $500

B. $600

C. $560

D. $440

4. Most experts believe people will be able to clone a dog ______.

A. in a year

B. in two years

C. in six years

D. between one to five years

5. Cloning will cost people ______.

A. a lot of money in five years

B. not much money

C. much and then nothing

D. much in the beginning and then be reduced

单项选择题