问题 选择题

如图是心脏工作示意图,下列有关说法错误的是(  )

A.心脏四个腔壁最厚的是[D]左心室

B.心室正处于收缩状态,血液由心室进入动脉

C.心房正处于舒张状态,血液由静脉进入心房

D.心室正处于舒张状态,血液由心房进入心室

答案

A、由图可知,心室的收缩把血液输送到全身的毛细血管或肺部的毛细血管,而心房收缩只需把血液送入到心室.与各自的功能相适应,心室的壁比心房的壁厚.同样的道理,左心室的收缩把血液输送到全身,而右心室的收缩把血液输送到肺,二者相比,左心室输送血液的距离长,与功能上的差别相适应,左心室的壁比右心室的壁厚.即D左心室的壁最厚.故不符合题意.

B、由图可知,心室正处于收缩状态,心房舒张,房室瓣关闭,动脉瓣打开,心室里的血液进入动脉,输送到全身各处的血液回流心房.故不符合题意.

C、由图可知,心房正处于舒张状态,房室瓣关闭,动脉瓣打开,血液由静脉进入心房.故不符合题意.

D、由图可知,心室正处于收缩状态,心房舒张,房室瓣关闭,动脉瓣打开,心室里的血液进入动脉,输送到全身各处的血液回流心房.故符合题意.

故选:D.

单项选择题

Placing a human being behind the wheel of an automobile often has the same curious effect as cutting certain fibres in the brain.

The result in either case is more primitive behaviour. Hostile feelings are apt to be expressed in an aggressive way.

The same man who will step aside for a stranger at a doorway will, when behind the wheel, risk an accident trying to beat another motorist through an intersection. The importance of emotional factors in automobile accidents is gaining recognition. Doctors and other scientists have concluded that the highway death toll resembles an epidemic and should be investigated as such.

Dr. Ross A. McFarland, Associate Professor of Industrial Hygiene at the Harvard University School of Public Health, said that accidents “now constitute a greater threat to the safety of large segments of the population than diseases do. ”Accidents are the leading cause of death between the ages of 1 and 35. About one third of all accidental deaths and one seventh of all accidental injuries are caused by motor vehicles.

Based on the present rate of vehicle registration, unless the accident rate is cut in half, one of every 10 persons in the country will be killed or injured in a traffic accident in the next 15 years.

Research to find the underlying causes of accidents and to develop ways to detect drivers who are apt to cause them is being conducted at universities and medical centres. Here are some of their findings so far:A man drives as he lives. If he is often in trouble with collection agencies, the courts, and police, chances are he will have repeated automobile accidents. Accident repeaters usually are egocentric, exhibitionistic, resentful of authority, impulsive, and lacking in social responsibility. As group, they can be classified as borderline psychopathic personalities, according to Dr. McFarland.

The suspicion, however, that accident repeaters could be detected in advance by screening out persons with more hostile impulses is false. A study at the University of Colorado showed that there were just as many overly hostile persons among those who had no accidents as among those with repeated accidents.

Psychologists currently are studying Denver high school pupils to test the validity of this concept. They are making psychological evaluations of the pupils to see whether subsequent driving records will bear out their thesis.

According to the text, studies at leading universities have shown that()

A. accident repeaters can be detected in advance

B. accident repeaters are in trouble with collection agencies

C.accident repeaters cannot be discovered on the basis of generally hostile attitudes

D. accident repeaters drive entirely differently from the way they usually live

选择题