Without the atmosphere there would be no weather, no wind, rain, snow, or clouds. Air is all around us; we live at the bottom of a great ocean of air. It is invisible, but we can feel it when it moves. There are miles of air above us, pressing down with great weight on the earth and everything on it. Because air presses down on us from all directions at the same time, and because we are able to bear (忍受) this weight, we do not seem to feel it. But scientists have proved that air has this weight, and that anything that has weight creates(产生) a force called pressure. As changes in air pressure take place, they, make air move.

Air is a gas that expands(膨胀) when heated, gets lighter, and moves upward. When air is cooled, it gets heavier, sinks close to the earth's surface, and flows like water in a great river. As warn air rises, cold air rushes in to take its place. 'Thus winds originate (起源). The winds that blow high above us are caused by the warmer air running away from colder air. The wind we feel near the earth's surface is the heavy colder air trying hard to catch the warmer air. Changes in temperature cause the air to move. And of course there are many changes, so air movements are taking place practically all the time.

The first paragraph mainly tells us the causes of

A．why we don't feel air　　　　　　　B．why atmosphere is important to us

C．why there is air surrounding us　　D．why there is air pressure

Air moves under such conditions that

A．there is air pressure              B．the air is heavy

C．air pressure doesn't remain the same all the time  D．air comes up and down

Which of the following pictures best tells the movements of warm air and cold air?

According to the passage, in same areas if farmers who grow grapes (葡萄) light fires in the early morning, that is because the farmers want to________________．

A．drive away warm air  B．prevent cold air from coming to harm their plants

C．cause more windD．stop warm air running away

Maybe ten-year-old Elizabeth put it best when she said to her father, "But, Dad, you can't be healthy if you're dead."

　　Dad, in a hurry to get home before dark so he could go for a run, had forgotten to wear his safety belt-- a mistake 75% of US population make every day. The big question is why.

　　There have been many myths (神化,虚构的事) about safety belt ever since their first appearance in cars some forty years ago. The following are three of the most common.

　　Myth the Number One: It's best to be "thrown clear" of a serious accident.

　　Truth: Sorry, but any accident serious enough to "throw you clear" is able going to be serious enough to give you a very bad landing. And chances are you'll have traveled through a windshield (挡风玻璃)or door to do it. Studies show that chances of dying after a car accident are twenty-five times in cases where people are "thrown clear".

　　Myth Number Two: Safety-belts "trap" people in cars that are burning or sinking in water.

Truth: Sorry again, but studies show that people knocked unconscious due to not wearing safety belts have a greater chance of dying in these accidents. People wearing safety belts are usually protected to the point of having a clear head to free themselves from such dangerous situation, not to be trapped in them.

　　Myth Number Three: Safety belts aren't needed at speeds of less than 30 miles per hour (mph).

　　Truth: When two cars traveling at 30 mph hit each other, an unbelted driver would meet the windshield with a force equal to diving headfirst into the ground from a height of 10 metres.

1.Why did Elizabeth say to her father, "But, Dad, you can't be healthy if you're dead"?

A．He didn't have his safety belt on.

B．He was running across the street.

C．He was driving at great speed.

D．He didn't take his medicine on time.

2.he reason father was in a hurry to get home was that he __________.

A．wasn't feeling very well                   B．hated to drive in the dark

C．wanted to take some exercise              D．didn't want to be caught by the people

3.According to the text, to be "thrown clear" of a serious accident is very dangerous because you ________.

A．may be knocked down by other cars.

B．may get serious hurt thrown out of the car

C．may find it impossible to get away from the seat

D．may get caught in the car door

4.Some people prefer to drive without wearing a safety belt because they believe _______.

A．they will be unable to think clearly in an accident

B．the belt prevents them from escaping in an accident

C．they will be caught when help comes

D．cars catch fire easily

5.What is the advice given in the test?

A．Never drive faster than 30 miles an hour.

B．Try your best to save yourself in a car accident.

C．Drive slowly while you're not wearing a safety belt.

D．Never forget to wear the safety belt while driving.

Maybe ten-year-old Elizabeth put it best when she said to her father, "But, Dad, you can't be healthy if you're dead."
　　Dad, in a hurry to get home before dark so he could go for a run, had forgotten to wear his safety belt-- a mistake 75% of US population make every day. The big question is why.
　　There have been many myths (神化,虚构的事) about safety belt ever since their first appearance in cars some forty years ago. The following are three of the most common.
　　Myth the Number One: It's best to be "thrown clear" of a serious accident.
　　Truth: Sorry, but any accident serious enough to "throw you clear" is able going to be serious enough to give you a very bad landing. And chances are you'll have traveled through a windshield (挡风玻璃)or door to do it. Studies show that chances of dying after a car accident are twenty-five times in cases where people are "thrown clear".
　　Myth Number Two: Safety-belts "trap" people in cars that are burning or sinking in water.
Truth: Sorry again, but studies show that people knocked unconscious due to not wearing safety belts have a greater chance of dying in these accidents. People wearing safety belts are usually protected to the point of having a clear head to free themselves from such dangerous situation, not to be trapped in them.
　　Myth Number Three: Safety belts aren't needed at speeds of less than 30 miles per hour (mph).
　　Truth: When two cars traveling at 30 mph hit each other, an unbelted driver would meet the windshield with a force equal to diving headfirst into the ground from a height of 10 metres.
【小题1】Why did Elizabeth say to her father, "But, Dad, you can't be healthy if you're dead"?

Maybe ten-year-old Elizabeth put it best when she said to her father, "But, Dad, you can't be healthy if you're dead."

　　Dad, in a hurry to get home before dark so he could go for a run, had forgotten to wear his safety belt-- a mistake 75% of US population make every day. The big question is why.

　There have been many myths about safety belt ever since their first appearance in cars some forty years ago. The following are three of the most common.

　Myth the Number One: It's best to be "thrown clear" of a serious accident.

　　Truth: Sorry, but any accident serious enough to "throw you clear" is able going to be serious enough to give you a very bad landing. And chances are you'll have traveled through a windshield (挡风玻璃)or door to do it. Studies show that chances of dying after a car accident are twenty-five times in cases where people are "thrown clear".

　Myth Number Two: Safety-bets "trap" people in cars that are burning or sinking in water.

    Truth: Sorry again, but studies show that people knocked unconscious (昏迷) due to not wearing safety belts have a greater chance of dying in these accidents. People wearing safety belts are usually protected to the point of having in these accidents. People wearing safety belts are usually protected to the point of having a clear head to free themselves from such dangerous situation, not to be trapped in them.

　Myth Number Three: Safety belts aren't needed at speeds of less than 30 miles per hour (mph).

　Truth: When two cars traveling at 30 mph hit each other, an unbelted driver would meet the windshield with a force equal to diving headfirst into the ground from a height of 10 metres.

Why did Elizabeth say to her father, "But, Dad, you can't be healthy if you're dead"?

 A. He was driving at great speed.

B. He was running across the street.

C. He didn't have his safety belt on.

 D. He didn't take his medicine on time.

The reason father was in a hurry to get home was that he __________.

A. wasn't feeling very well     B. hated to drive in the dark

C. wanted to take some exercise  D. didn't want to be caught by the people

According to the text, to be "thrown clear" of a serious accident is very dangerous because you ________.

A. may be knocked down by other cars.

B. may get serious hurt thrown out of the car

C. may find it impossible to get away from the seat

 D. may get caught in the car door

Some people prefer to drive without wearing a safety belt because they believe _______.

A. the belt prevents them from escaping in an accident

B. they will be unable to think clearly in an accident

C. they will be caught when help comes

 D. cars catch fire easily

What is the advice given in the test?

A. Never drive faster than 30 miles an hour.

B. Try your best to save yourself in a car accident.

C. Never forget to wear the safety belt while driving.

 D. Drive slowly while you're not wearing a safety belt.