The word “exert” in bold on paragraph 1 is closest in meaning to

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 below. 

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 on seater, so thay at 39 meters in seawater a diver is exposed to pressure of about 4 atmosphere. 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 atmosphere, 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. 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 the rise of the exhaled air bubbles, and must exhale during ascent.

The word “exert” in bold on paragraph 1 is closest in meaning to ________.

• A. permit
• B. cause
• C. need
• D. change

• Câu 2: Mã câu hỏi: 37629

  What does the passage mainly discuss?

  • A. The equipment divers use
  • B. How to prepare for a deep dive
  • C. The symptoms of nitrogen bubbles in the bloodstream
  • D. The effect of pressure on gases in the human body

• Câu 3: Mã câu hỏi: 37630

  The word “they” in bold on paragraph 2 refers to ________.

  • A. joints
  • B. pains
  • C. tissues
  • D. bubbles

• Câu 4: Mã câu hỏi: 37631

  What happens to nitrogen in body tissues if a diver ascends too quickly?

  • A. It is reabsorbed by the lungs
  • B. It goes directly to the brain
  • C. It forms bubbles 
  • D. It has a narcotic effect

• Câu 5: Mã câu hỏi: 37632

  It can be inferred from the passage that which of the following presents the greatest danger to a diver?

  • A. Nitrogen diffusion
  • B. An air embolism
  • C. Nitrogen bubbles
  • D. Pressurized helium

• Câu 6: Mã câu hỏi: 37633

  The word “rupture” in bold in paragraph 3 is closest in meaning to ________.

  • A. shrink
  • B. burst
  • C. hurt
  • D. stop

• Câu 7: Mã câu hỏi: 37634

  What should a diver do when ascending?

  • A. Breathe helium
  • B. Relax completely 
  • C. Breathe faster
  • D. Rise slowly