问题 解答题

如图是人体某部位的毛细血管示意图,请据图回答:

(1)如果在______中流动的是静脉血,______中流动的是动脉血,那么______可能是______的毛细血管网,此处的气体交换是通过______作用完成的;在______处可以观察到红细胞呈______通过.

(2)如果在______为肾小球的毛细血管网,那么在______、______内流动的都是______血,______处发生了______作用.

(3)如果在______为小肠绒毛内的毛细血管网,在______处除气体交换外还完成的生理活动是______.

答案

根据图中血液流动方向,A血管由主干流向分支,因此A是动脉,C血液由分支流向主干,因此是静脉,B连通与最小的动脉和静脉之间的血管是毛细血管,红细胞呈单行通过.

(1)如果在A中流动的是静脉血,C中流动的是动脉血,那么B可能是肺部的毛细血管网,此处的气体交换是通过气体扩散作用完成的,氧气扩散到血液,血液中的二氧化碳扩散到肺泡;在B处可以观察到红细胞呈单行通过.

(2)肾小球是一个毛细血管球,它的一端连着入球小动脉,另一端连着出球小动脉,入球小动脉、肾小球、出球小动脉里流的都是动脉血,因此如果B为肾小球的毛细血管网,那么血管A是入球小动脉、C血管是出球小动脉,在A、C内流动的都是动脉血;而B肾小球在功能上具有过滤作用,形成原尿.

(3)小肠是吸收营养物质的主要器官,血液流经小肠后,有机营养增加,因此,如果B为小肠绒毛内的毛细血管网,在B处除气体交换外还完成的生理活动是吸收营养物质.

故答案为:

(1)肺部;扩散;单行; 

(2)动脉;过滤; 

(3)吸收营养.

阅读理解

阅读理解

     Poor listening skills form an obstacle to effective communication.  A study by Dr.  Paul Panklin at a

university found that 9 percent of communication time is devoted to writing,   16 percent to reading,   30

percent to speaking and 45 percent to listening.  

     We spend more time listening than we do in any other form of communication.  However,   most of

us don't pay much attention to it.  

      Research indicates that normal listening results in a 50percent retention immediately after a 10minute

presentation,   which then declines to only about 25 percent after 48 hours.  Extension Specialist Bob

Linda says the average person will hear 7.  5 minutes of a onehour presentation and will forget half of that.  

      One reason we listen so poorly is that our minds work much faster than our mouths.  The average

person thinks 600-700 words per minute but speaks at a rate of about 125.  His listeners' minds are

occupied with hearing only onefifth of the time he is speaking.  The listeners may consider and react to

what is being said during the other fourfifths of the time,   or become absorbed in coming up with his

response,   or think other thoughts and miss the rest of what is being said.  

      If we really listen,   we may be forced to accept a different perspective of reality.  Most of us have

a firmly developed view of reality that we do not want to change.  Carl Rogers,   the psychiatrist,   points

out that if you are really willing to listen to another,   to enter his private world and see reality as he sees

it,   you run the risk of being changed.  "This risk of being changed is one of the most frightening prospects most of us can face. "

1. From the passage,   we can learn that listening ______.  

A.  always forms a barrier to our communication

B. occupies the largest part in communication

C. will take the place of other ways of communication

D. is a difficult skill to master

2. The underlined word "retention" in the 3rd paragraph means "________".  

A. attention  

B. presentation

C. memory  

D. occupation

3. In normal listening,   the reason why an average person can only keep half of what the

    speaker says in mind is that ________.  

A. half of that will be forgotten

B. our mouths work much more slowly than our minds

C. most of us pay little attention to it

D. he is afraid of being changed

4. According to Carl Rogers,   ________.  

A. we should let listeners enter our private world

B. the opinions of the speakers may affect us if we listen to them willingly

C. we shouldn't make us changed while listening

D. it is wrong that we don't want to change while listening

多项选择题