问题 单项选择题

血中Hb实际结合的氧量是()

A.氧分压

B.氧含量

C.氧容量

D.氧和Hb的亲和力

E.氧饱和度

答案

参考答案:B

解析:

[解释] 氧分压是指溶解于血液的氧所产生的张力,氧分压高低直接影响氧含量的多少。氧容量是指100ml血液中的Hb被氧充分饱和时的最大带氧量,它的大小取决于Hb的量及它与氧的结合能力。氧含量则是100ml血液实际带氧量,主要是Hb实际结合氧的量,它取决于氧分压和氧容量矗氧饱和度为氧含量与氧容量的百分比。

阅读理解

阅读理解

      Jennifer got off the bus from the university and began walking towards the flat she shared with two

other students.   1   She picked up a wire basket and walked towards the back of the shop, where the

rice was kept. The shop was divided by three long aisles, with rows of shelves crammed with all sorts

of things. Except for her and Mr. Patel, the owner, there were only two other people there. They were

two teenage boys, and they were standing at the end of one of the aisles.

     She glanced at them as she passed. They were both wearing long, oldfashioned overcoats and they

looked rather ridiculous in them because the coats were too big.   2   "Watch out, stupid," she heard

one of them whisper to the other. She walked on to the next aisle and found the rice she was looking

for.

     Then she heard something else.   3    She peered through a gap in the shelf and caught a glimpse of

one of the boys bending down. She saw him pick up a tin of food. But instead of putting it in the

shopping basket, he dropped it into the inside pocket of his long overcoat. Jennifer glanced back down

the aisle. She could see Mr. Patel at the cash till, still checking through his list.

        4   The boys still had their backs to her. "Come on, let's get out of here," she heard one of them

say. At the same time, she saw one of them put another tin in his overcoat pocket. They moved away

from her. She could no longer see what they were doing or hear what they were saying.

     When she got to the still, the two boys were in front of her. She watched them pay for the few things

they had in the basket. They had both buttoned their coats and fastened them with their belts.   5   He

even smiled at them as they were about to leave. Jennifer opened her mouth to say something.

A. It sounded like a tin dropping on the floor.

B. But such things were popular with some teenagers at the time.

C. Then she looked through the gap in the shelf again.

D. On her way she had to buy some food and stopped in one of the shops in the street.

E. They were picking many things to their basket.

F. Mr. Patel was so friendly to his customers.

G. Mr. Patel did not seem suspicious at all.

问答题 简答题