问题 单项选择题

有关阴离子间隙(AG)描述错误的是()

A.AG是指血清中所测的阳离子总数和阴离子总数之差计算而出

B.计算公式AG=(Na++K+)-(Cl-+HCO-3

C.可化简为AG=Na+-(Cl-+HCO-3

D.AG对代谢性酸中毒的病因及类型的鉴别诊断有一定价值

E.根据AG水平高低可以判断呼吸性酸中毒的病因

答案

参考答案:E

解析:临床AG升高多见于代谢性酸中毒的全过程,是判断代谢性酸中毒病因的指标,并可作为诊疗的参考。

阅读理解

阅读理解.

      Thirty years ago, Lake Ponkapog in Hartwell, New Jersey, was full of life. Many birds and animals

 lived beside the water. which was full of fish. Now there are few birds, animals, and fish. The lake water

  is polluted (污染的). It is in a colour of dirty brown, and it is filled with strange plants.

      How does this happen? First we must think about how water gets into Lake Ponkapog. When it

 rains water comes into the lake from all around. In the past there were forests all around Lake Ponkapog

 so the rain water was clean.

      Now there are many homes around the lake. People often use chemicals (化学品) in their gardens.

 They use other chemicals inside their houses for cleaning or killing insects (昆虫). There are also many

 businesses. Businesses use chemicals in their machines or shops. Other chemicals fall onto the ground

 from cars or trucks. When it rains, the rain water picks up all the chemicals from homes and businesses

 and then carries them into the lake. They pollute the water and kill the animals.

      Boats on the lake are also a problem. Lake Ponkapog is a popular place for motorboats. But oil and

 gas (油和汽) from boats often get into the lake. So more bad chemicals go into the water this way. 

 People in Hartwell are worried. They love their lake and want to save it. Will it possible? A clean lake

  must have clean rainwater going into it. Clean rainwater is possible only if people are more careful about

 chemicals at home and at work. They must also be more careful about gas and oil and other chemicals

 on the ground. And they mustn't use motorboats any more on the lake. All these may change people's

 lives. Only then can Lake Ponkapog be a beautiful, clean lake again.

1. In the past, the water in Lake Ponkapog was made clean by _____.

A. forests

B. rain

C. birds

D. fish

2. Chemicals from homes and businesses _____.

A. are always clean

B. can help the animals

C. are good for the lake

D. get into the rainwater

3. Cleaner rainwater will mean _____.

A. more boats on the lake

B. more dirty things in the lake

C. a cleaner lake

D. a dirtier lake

4. To save Lake Ponkapog, people need to _____.

A. be more careful about chemicals

B. use less water

C. grow fewer plants in the gardens

D. use more motorboats on the lake

5. The passage is about _____.

A. boats on Lake Ponkapog

B. why the water is dirty in Lake Ponkapog

C. clean rainwater

D. dirty lakes

单项选择题