问题 单项选择题

慢性肺心病引起肺动脉高压最主要的原因是()

A.血液黏稠度增加

B.血容量增加

C.慢性炎症所致的肺动脉狭窄

D.高碳酸血症

E.缺氧性肺血管收缩

答案

参考答案:E

解析:肺心病引起肺动脉高压的原因包括肺血管阻力增加的功能性因素和肺血管阻力增加的解剖学因素,以及血容量增加和血液黏稠度增加。功能性因素较其他因素更为重要,缺氧、高碳酸血症和呼吸性酸中毒使肺血管收缩痉挛,其中缺氧是肺动脉高压形成最重要的因素。

单项选择题

In the United States and in many other countries around the world, there are four main ways for people to be (91) about developments in the news: newspapers, magazines, and radio or television news broadcasts. A person may use one, or all, of these (92) for information. Each source is useful in its (93) way. Newspapers and magazines can give much information about a particular event. They may (94) some history of the event, some of its (95) , some of its effects, or perhaps give an (96) or point of view on a particular development. Radio and television can help a person to be well informed about what is happening each day. It is also (97) to listen to radio or watch TV (98) do something else at the same time. Many people can listen to the news on their car radio while driving (99) . For the student of English as a foreign language, an English language newspaper may be the most helpful news source that will also (100) you practice in reading English.
Most daily English language newspapers are not very hard to find. They are interesting and helpful in many (101) . In some of them, you may be able to find news about your (102) country. You will find news and information about important national and international political (103) . (104) what you are interested in, you can probably find something in the newspaper about it. A(n) (105) in the newspaper may help you solve a problem. Other stories may be about good movies, concerts, or TV shows.
Usually, an English language newspaper has several (106) or parts. Each part of the newspaper (107) stories about different kinds of news. Some sections have a lot of advertisements which may be helpful if you want to save money. By reading the advertisements, you may find something you want (108) sale. Or you may find that two stories are advertising the (109) thing, but at one store the price is lower. Other sections may have (110) advertisements or have only a specific type of advertisement to interest the people.

A.native

B.local

C.original

D.natural

选择题