问题 单项选择题

新生儿发生肺透明膜病主要由于

A.低血糖
B.血清胆红素浓度升高
C.缺氧
D.感染
E.缺乏肺泡表面活性物质

答案

参考答案:E

解析:新生儿肺透明膜病主要由于缺乏肺泡表面活性物质引起。肺泡表面活性物质具有降低肺泡表面张力,使肺泡张开的作用;缺乏时肺泡壁表面张力增高,肺泡逐渐萎缩、发生肺不张,而出现一系列临床表现。

单项选择题
单项选择题

We once had a poster competition in our fifth grade art class.

"You could win prizes," our teacher told us as she wrote the poster information on the blackboard. She passed out sheets of construction paper while continuing. "The first prize is ten dollars. You just have to make sure that the words on the blackboard appear somewhere on your poster. "

We studied the board critically. Some of us looked with one eye and held up certain colors against the blackboard rocking the sheets to the right or left while we conjured up our designs. Others twisted their hair around their fingers or chewed their erasers while deep in thought. We had plans for that ten- dollar grand prize, each and every one of us. I’m going to spend mine on candies one hopeful would announce while another practiced looking serious wise and rich.

Everyone in the class made a poster. Some of us used parts of those fancy paper napkins, while others used nothing but colored construction paper. Some of us used big designs and some of us preferred to gather our art tidily down in one comer of our poster and let the space draw the viewer’s attention to it. Some of us would wander past the good students’ desks and then return to our own projects with a growing sense of hopelessness. It was yet another grown up trick of the sort they seemed especially fond of making all of us believe we had a fair chance and then always—always—rewarding the same old winners.

I believe I drew a sailboat, but I can’t say that with any certainty. I made it. I admired it. I determined it to be the very best of all of the posters I had seen and then I turned it in.

Minutes passed.

No one came along to give me the grand prize and then someone distracted me and I probably never would have thought about that poster again.

I was still sitting at my desk thinking, what poster When the teacher gave me an envelope with a ten-dollar bill in it and everyone in the class applauded for me.

After seeing the good students’ designs, some students()

A.loved their own designs more

B.thought they had a fair chance

C.put their own designs in a comer

D.thought they would not win the prize