问题 单项选择题 A1/A2型题

低渗性脱水的初期,人体的自身调节是为了()

A.维持血容量

B.防止代谢性酸中毒

C.防止氮质血症

D.维持体内晶体渗透压

E.维持神经系统的正常功能

答案

参考答案:D

解析:机体调整渗透压的代偿机制表现为抗利尿激素的分泌减少,使水在肾小管内的再吸收减少,尿量排出增多,从而提高细胞外液的渗透压。但这样会使细胞外液总量更为减少,于是细胞间液进入血液循环,以部分地补偿血容量。为避免循环血量的再减少,机体将不再顾及渗透压的维持。故低渗性脱水的初期,人体的自身调节是为了维持体内晶体渗透压。答案应选D。

阅读理解

      根据短文内容,从短文后的七个选项中选出能填入空白处的最佳选项.选项中有两项为多

余选项.

     A 7.0 magnitude(级)earthquake killed more than 230,000 people in Haiti. Then an 8.8 magnitude

quake killed more than 900 people in Chile. And few weeks later, a 6.0 magnitude quake struck rural

eastern Turkey, killing at least 57 people.

     The earthquakes kept coming hard and fast.   1  It's not. The problem is what's happening above

ground, not underground, experts say.

       2  They're rapidly putting up buildings that can't stand up to earth quakes, scientists believer.

And news reports and better earthquake monitoring make it seem as if earth quakes are increasing all the

time.

     On average, there are 134 earthquakes a year that have a magnitude between 6.0 and 6.9. So far this

year there have been 40 earthquakes-more than in most years for that time period. But that's because the

8.8 quake in Chile caused a large number of strong aftershocks.

     Also, it's not the number of quakes, but their destructive effects that gain attention. The death is largely

due to building standards,   3   Paul Earle, a US seismologist, called for better building standards in the

world's big cities.

     Of the 130 cities worldwide with populations of more than I million, more than half are likely to be

hit by earthquakes.   4  "If you have a problem feeding yourself, you're not really going to worry about

earthquakes," said Paul.

     The earthquakes made everyone start to think   5   "People are paying attention to the violent planet

we're always lived on. Come back an another six moths if there has been no earthquakes, most people

will have forgotten it again," said US disaster researcher Dennis Mileti.

A.But it won't last.

B.More people are moving into big cities.

C.Earthquakes don't kill people, buildings do.

D.There have been more deaths overt the past decade from earthquakes.

E.Many people began to wonder if something terrible is happening underground.

F.While it seems as if the are more earthquakes occurring, there really aren't.

G.But developing nations with growing populations don't pay attention to earthquake preparedness.

单项选择题