A. The brain lacks enough oxygen.

B. The air pressure in a plane is too high

C. Our body needs less oxygen during takeoff.

D. The bloodstream contains no oxygen molecules.

3. The underlined part "fix the situation" means "___".

A. use more oxygen it needs B. increase the air pressure

C. reduce the amount of blood D. bump more blood to the brain

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

A. They weaken the body's ability to use oxygen.

B. Smoking may pollute the air inside the airplane.

C. Drinking alcohol may raise one's blood pressure.

D. Drinking is forbidden at the airport.

　　Everyone needs friends. We all like to feel close to someone. It is nice to have a friend to talk, laugh and do things with. Surely, there are times when we need to be alone. We don't always want people around. But we would feel lonely if we never had a friend.

　　No two people are the same. Sometimes friends don't get along well, which doesn't mean that they no longer like each other. Most of the time they will go on being friends. Sometimes friends move away, then we feel very sad. We miss them much, but we can call them and write to them. Maybe we would never see them again, and we can make new friends. It is surprising to find out how much we like new people when we get to know them. Families sometimes name their children after a close friend. Many places are named after men and women, if they are friendly to people in a town. Some libraries are named this way. So are some schools. We think of these people when we go to these places.

　　There's more good news for people, if they have friends. These people live longer than those people if they don't have friends. Why? It could be that they are happier. Being happy helps you stay well. Or it could be just knowing that someone cares, if someone cares about you, you take better care of yourself.

5. The first paragraph tells us __________.

A. none needs friends

B. we always need friends around us

C. making friends is the need in people's life D. we need to be alone

6. Which of the following is what the writer doesn't say in the passage?

A. People are happy when their friends leave them.

B. People may never see their friends after their friends move away.

C. People having friends can live longer than those who don't.