A
People faint(昏厥) when the normal blood supply to the brain is suddenly cut down. This can happen if they are surprised or shocked(震动) by sudden news or by something they see suddenly. Some people faint if they see others hurt. Some people faint in crowds. Others faint if they are in a room that is hot and stuffy(闷热的).
If a person faints while standing, lay him down. If his face is pale, lift his feet. If he is sitting down when he faints, place his head between his knees, loosen any tight clothing that might keep him from breathing easily. If possible, place a wet cloth on his forehead.
1.People may faint if they________.
A. see their friends in the street
B. see something unexpected
C. see something splendid
D. see something happy
2.If someone has fainted, we must help him________.
A. not to be shocked B. by moving himself slowly
C. not to be frightened D. by returning blood to his brain
3.If someone faints, the best way is to________.
A. make him sit down B. make him lie down
C .make him not surprised D. give him some blood
4.Raise a fainting person's feet if________.
A. he sees others hurt
B. he is in a room that is hot and stuffy
C. his face looks pale
D. he is standing
5.In this passage, the writer explains________.
A. why people faint and how we help them
B. when people faint and when we help them
C. why people faint and where we help them
D. how people faint and why we help them
B
How long can a person live without breathing? Probably for only four to six minutes. The air we breathe in supplies the oxygen(氧) that is necessary for keeping every part of the body alive. And the brain, which itself controls breathing, is the first to suffer(受苦) if oxygen is lacking(缺乏). If no air enters the lungs(肺), the heart will continue to beat for a little longer, supplying the blood to the brain and other parts of the body. But soon, the supply of oxygen already in the blood is used up.
First, the patient loses conciousness(知觉), because the brain is no longer getting enough oxygen to work. Then lack of oxygen in the heart causes it to stop beating. Without oxygen ,the brain can survive(持续) undamaged for only about four minutes. The heart may survive for as long as 12 minutes. But within six minutes the person will almost certainly be dead.
1.The oxygen that our body needs comes from________.
A. the air we breathe inB. the moving blood
C .the beating heartD. the working brain
2.If no air enters the lungs,________.
A. the heart will stop beating immediately
B. the brain is the first to suffer
C. the blood can continue to move a long time
D. a person will stop breathing
3.According to the passage we can conclude________.
A. the heart is more important than the brain
B. the brain can continue to work a little longer than the heart without oxygen
C. the brain stops working before the heart does without oxygen
D. if a person stops breathing it means he is dead
4.In which order will the following happen without oxygen?
a. The heart stops beating. b. The brain stops working.
c. A person is dead. d. A person loses conciousness .
A .b, a, d, cB. a, b, d, c
C. d, a, b, cD. d, b, c, a
5.Oxygen is carried to every part of the body by________.
A. the lungsB. the heartC. the bloodD. the brain
keys:A1～5 BDBCA B 1～5 ABCDC