问题 单项选择题

低血容量性休克代偿期()

A.静脉回心血量增加

B.微循环收缩

C.心排出量/正常

D.微循环扩张

E.弥漫性血管内凝血

答案

参考答案:B

解析:

低血容量性休克代偿期时,因循环血量锐减,使交感系统兴奋,释放儿茶酚胺使皮肤及肝脾等小血管和微血管、毛细血管前括约肌收缩,使微动脉阻力增加。此期又称微循环收缩期。低血容量性休克抑制期时长时间的广泛微动脉收缩.使组织灌注不良,酸性代谢产物蓄积,直接损害毛细血管前括约肌,使其失去对儿茶酚胺的反应能力,微动脉和毛细血管前括约肌扩张,而小静脉仍处在收缩状态,引起大量血液滞留在毛细血管网内。

阅读理解

When Scotsman Alexander Graham Bell invented the telephone in 1876, it was a revolution in communication. For the first time, people could talk to each other over great distances almost as clearly as if they were in the same room. Nowadays, though, we increasingly use Bell' s invention for taking photographs, accessing the internet, or watching video clips, rather than talking. Over the last two decades a new means of spoken communication has appeared: the mobile phone.

The first real mobile telephone call was made in 1973 by Dr Martin Cooper, the scientist who invented the modem mobile handset. Within a decade, mobile phones became available to the public. The streets of modem cities began to feature sharp-suited characters shouting into giant plastic bricks. In Britain the mobile phone quickly became the same with the "yuppie" , the new type of young urban professionals who carried the expensive handsets as status symbols. Around this time many of us said that we would never own a mobile phone.

But in the mid-90s, something happened. Cheaper handsets and cheaper calling rates meant that, almost overnight, it seemed that everyone had a mobile phone. And the giant plastic bricks of the 80s had changed into smooth little objects that fitted nicely into pockets and bags.

Moreover, people' s timekeeping changed. Younger readers will be amazed to know that, not long ago, people made spoken arrangements to meet at a certain place at a certain time. But later Meeting times became approximate under the new order of communication: the Short Message Service (SMS) or text message. Going to be late? Send a text message! It takes much less effort than arriving on time, and it' s much less awkward than explaining your lateness face to face and the text message has changed the way we write in English. Traditional rules of grammar and spelling are much less important when you' re sitting on the bus, hurriedly typing "Will B 15mm late - C U @ the bar. Sorry! - )".

Alexander Graham Bell would be amazed if he could see how far the science of telephony has progressed in less than 150 years.If he were around today, he might say "That' s gr8! But I' m v busy rite now.Will call U 2nite."

小题1:What does the underlined part in Para. 2 refer to?

A.Houses of modern cities.

B.Sharp-suited characters.

C.New type of professionals.

D.Mobile phones.小题2:According to Paragraph 4, why did Meeting times become approximate?

A.People were more likely to be late for their meeting.

B.SMS made it easier to inform each other.

C.Young people don' t like unchanging things.

D.Traditional customs were dying out.小题3:If you want to meet your friend at the school gate this evening, which of the following message can you send him?

A.Call U@ SKUg8 2nite.

B.IM2BZ2CU 2nite.

C.CU@ the bar g8 2nite.

D.W84U@ SKUg8 2nite.小题4:What does the passage mainly tell us about?

A.Alexander Graham' s invention.

B.SMS @ a new way of communication.

C.New functions of the mobile telephone.

D.The development of the mobile phone.

多项选择题