MOST OF THE PEOPLE RECOVERED QUICKLY. THEY WERE INJURED IN THE CRASH.A...

Câu 35:

Most of the people recovered quickly. They were injured in the crash.

A.

The people who were injured in the crash, most of them recovered quickly.

B.

Most of the people who recovered quickly were injured in the crash.

C.

Most of the people recovered quickly after the crash.

D.

Most of the people injured in the crash recovered quickly.

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the

correct answer to each of the questions that follow.

Under certain circumstances, the human body must cope with gases at greater-than-normal atmospheric

pressure. For example, gas pressures increase rapidly during a drive made with scuba gear because the

breathing equipment allows divers to stay underwater longer and dive deeper. The pressure exerted on the

human body increases by 1 atmosphere for every 10 meters of depth in seawater, so that at 39 meters in

seawater a diver is exposed to pressure of about 4 atmospheres. The pressure of the gases being breathed

must equal the external pressure applied to the body, otherwise breathing is very difficult. Therefore all of

the gases in the air breathed by a scuba diver at 40 meter are present at five times their usual pressure.

Nitrogen, which composes 80 percent of the air we breathe, usually causes a balmy feeling of well-being

at this pressure. At a depth of 5 atmospheres, nitrogen causes symptoms resembling alcohol intoxication,

known as nitrogen narcosis. Nitrogen narcosis apparently results from a direct effect on the brain of the

large amounts of nitrogen dissolved in the blood. Deep dives are less dangerous if helium is substituted

for nitrogen, because under these pressures helium does not

exert

a similar narcotic effect.

As a scuba diver descends, the pressure of nitrogen on the lungs increases. Nitrogen then diffuses from

the lungs to the blood, and from the blood to body tissues. Nitrogen then diffuses from the lungs to the

blood, and from the blood to body tissues The reverse occurs when the diver surfaces, the nitrogen

pressure in the lungs falls and the nitrogen diffuses from the tissues into the blood, and from the blood

into the lungs. If the return to the surface is too rapid, nitrogen in the tissues and blood cannot diffuse out

rapidly enough and nitrogen bubbles are formed.

They

can cause severe pains, particularly around the

joints.

Another complication may result if the breath is held during ascent. During ascent from a depth of 10

meters, the volume of air in the lungs will double because the air pressure at the surface is only half of

what it was at 10 meters. This change in volume may cause the lungs to distend and even

rupture. This

condition is called air embolism.

To avoid this event, a diver must ascend slowly, never at a rate exceeding the rise of the exhaled air

bubbles, and must exhale during ascent.