问题 单项选择题 A型题

关于房水的描述,不正确的是()

A.房水主要通过睫状突无色素上皮细胞主动分泌产生

B.房水中钙的浓度只有血浆中的一半

C.乳酸盐离子是房水中最丰富的有机阴离子

D.房水中的蛋白远高于血浆,最多的为转铁蛋白和白蛋白

E.房水中维生素C的浓度远高于血浆浓度

答案

参考答案:D

解析:本题为对房水相关知识的综合考查。房水由睫状突无色素上皮细胞产生,其生成包括分泌、超滤过、扩散三种方式,分泌产生的房水占总量的75%。房水中蛋白质含量约为0.2mg/ml,仅为血浆含量的1/400~1/300,房水中白蛋白含量相对高于血浆,而球蛋白含量相对低于血浆。乳酸盐离子是房水中最丰富的有机阴离子,而维生素C的浓度是血浆中的50倍。故本题中D项说法错误。

单项选择题
阅读理解

阅读理解.

     It is well known that Albert Einstein was one of the greatest scientists of all time and he

was also a really great person. Here are some interesting things about him.

     When Einstein started to work in America, someone asked him what he needed. He said

he needed a desk, some paper and a pencil. He also asked for a big waste-paper basket to

hold all of his mistakes. This shows that he knew even the cleverest man in the world can

only learn by making mistakes.

     Einstein regarded time as very important. He never wore socks and he thought putting

on socks was a waste of time as people already wore shoes. He also thought it was a waste

of time remembering things that could quickly be found in a book. That's why he never

remembered his own phone number, which was in the phone book. He knew what was worth

remembering. It is true that if we are going to do great things in our lives, we can not waste

our time.    

     Einstein liked to joke too. Once in an exam a student asked him why all the questions

were the same as last year's. Einstein replied the questions were the same but the answers

were different!

1. In one exam, Einstein _____.

A. asked different questions

B. asked difficult questions

C. wanted the answers all the same

D. wanted different answers

2. Einstein never remembered his own phone number because _____.

A. no one told him the number

B. he couldn't remember it at all.

C. he didn't think it was worth remembering.

D. he didn't have a phone.

3. According to the passage, which of the following is TRUE?______.

A. Einstein has been to many countries except America.

B. Einstein thought people could learn from mistakes.

C. Einstein thought socks were as important as shoes.

D. Einstein didn't like talking with others.

4. From the passage, we learn _____.

A. Einstein thought time was very important.

B. Einstein was too careful to make mistakes.

C. Einstein made few jokes with the students.

D. Einstein was a person who remembered everything clearly.