C

Travel is exciting and summer is a busy period for holiday travel. Many people will travel great distances in airplanes, cars or other vehicles. Experts say people should know about other health problems that can strike when traveling by air.

One of these is a condition called hypoxia (缺氧症). It results from a lack of oxygen to the brain. Experts say the body begins losing oxygen minutes after an airplane leaves the ground. The air pressure in a plane during flight is lower than at sea level. This makes it more difficult for the body to effectively use the same amount of oxygen as it would on the ground. Fewer oxygen molecules (分子) cross the tissues (组织) in the lungs and reach the bloodstream.

The result is a five to twenty percent drop in the amount of oxygen in the blood. This reduces the amount of oxygen that reaches the organs of the body.

One effect of this lack of oxygen to the brain is a headache. When this happens, the heart attempts to fix the situation by beating harder and faster. This can make the traveler feel tired.

These signs of hypoxia are not dangerous in a healthy person. But a drop in oxygen level can cause a health emergency in people with heart or lung problems. They might lose consciousness or even suffer a heart attack.

Experts say that smoking cigarettes and drinking alcoholic liquids also reduce the body’s ability to use oxygen. So they suggest that people not drink alcohol or smoke cigarettes either before or during a flight. They also say persons with heart or lung problems should seek advice from their doctors before flying.

59. The author writes the passage mainly to ___.

A. explain the causes and effects of hypoxia

B. offer some advice on avoiding health problems

C. warn people in airplanes of possible dangers

D. advise people not to smoke or drink alcohol

60. According to the passage, what leads to hypoxia?

A. Our body needs less oxygen during takeoff.

B. The air pressure in a plane is too high

C. The brain lacks enough oxygen.

D. The bloodstream contains no oxygen molecules.

61. The underlined part “fix the situation” means “___”.

A. use more oxygen it needs      B. bump more blood to the brain

C. reduce the amount of blood      D. increase the air pressure

62. Why should passengers not smoke or drink before flying?

A. Drinking alcohol may raise one’s blood pressure.

B. Smoking may pollute the air inside the airplane.

C. They weaken the body’s ability to use oxygen.

D. Drinking is forbidden at the airport.

D

For my sweet sixteen there were no TV cameras filming the planning process, and no beautiful car as a “surprise” gift at the end of the party. But it was a party with a far better ending. My friends and family came together to dance the night away and remember World AIDS Day to help the Holly House Orphanage (孤儿院) in Nairobi, Kenya. The $8,600 we raised was the best gift I could ever dream of! It was so pleasing to know that my celebration would be felt halfway around the world by children in need.

I am part of the Global Citizen Corps Leadership Program, which has taught me to become aware of the problems of those around the world. To me, it seems that a lack of education is the obstacle that keeps many in the cycle of poverty. The school in Nairobi is a place where I believe my efforts, although small, can have a huge effect.

When I started planning for my sweet sixteen, I faced many difficulties. But later I realized that World AIDS Day was on a Saturday, so I decided to use that evening in combination with the donation theme so that the date meant something. My actual birthday was not until February, but I moved the party to World AIDS Day in December. Everyone I told was inspired. As a matter of fact, after my party I received an invitation from a friend who also asked for donations for another African AIDS organization instead of gifts. This makes me feel like I can encourage my friends to make a difference in the world.

I did not tell the school what I had cooked up for my birthday. I wanted it to be a surprise. So I put all of the checks in one envelope with a Christmas card. Then I waited with excitement for a response. The school could not have been more pleased with their gift. This birthday party has been the best ever. Isn’t that what a sweet sixteen should be?

63. How did the author celebrate her sixteenth birth-day?

A. By receiving a “surprise” gift of a beautiful car.

B. By recording the party with a TV camera.

C. By raising $8,600 for African children.

D. By drinking with her friends and family.

64. The Global Citizen Corps Leadership Program aims to help children ______.

A. organize their birthday celebration

B. care about the problems of the world

C. improve their level of education

D. stay away from the influence of AIDS