The rockets take astronauts and man-made satellites into space. The satellites are used for communication, weather monitoring and research. But how do satellites stay up without falling down?

There are two opposite forces (力量) acting on the satellite. One of them is the force of gravitation (地心引力), which tries to pull the satellite towards the earth. The other force is created by the rotation (旋转) of the satellite around the earth. This force tries to take the satellite away from the earth. With these two forces, the satellite goes round and round. The gravitational pull of the earth (the force which pulls everything towards the ground) is like a rope which keeps the satellite from flying away.

Everything that goes up has to come down. It is only a matter of time before a satellite comes back to the earth. As time goes by, the satellite loses its speed, which makes the gravitational pull stronger than the force pulling it away. This makes the satellite crash (坠落) down to the earth.

1.Which of the following uses of satellites is NOT mentioned?

A. communication                   

B. monitoring the weather condition

C. doing some research             

D. taking pictures

2.The force that pulls the satellite towards the earth is created by ________.

A. the earth                       

B. the satellite itself

C. the rotation of the satellite           

D. the rope 

3.Why can’t the satellites fly away?

A. Because of the force from the earth.

B. Because the satellite is too big.

C. Because of the force created by the rotation of the satellite around the earth.

D. Because people on earth have made ropes to tie the satellites tightly.

4.The satellite will finally crashes down to the earth ________.

A. when it flies faster            

B. when its speed slows down

C. when people cut the rope        

D. when there is no electricity in it

5.Which of the following is TRUE according to the passage?

A. There are four forces acting on the satellite.

B. The force of gravitation makes the satellite go round and round.

C. As time goes by, the satellite will finally fall down.

D. The satellite will stay in space forever.

While I was waiting to go into university, I saw in a newspaper a teaching job wanted at a school about ten miles from where I   16 . Because I was in great need of   17  and wanted to do something useful, I applied(申请).
Three days later, a letter   18 . It asked me to see the   19  at Croydon. It proved to be a(n)   20  journey —a train to Croydon station, a ten-minute bus ride and then a walk of   21  a quarter of a mile. As a result I arrived there, feeling too hot to be nervous. Clearly, the principal   22  opened the door. He was   23  and round.
“The school” he said, “has a group of twenty-four boys between seven and thirteen.”
I should have to teach all the   24  except art, which he taught himself. I should have to divide the class into  25  groups and teach them at three different   26 , and I was not    27  at the thought of teaching maths —a subject which I didn’t do very well in at school. It was   28  that I had to teach them on Saturday afternoon   29  most of my friends would be   30  themselves at that time.
Before I had time to ask about my salary(薪水), he got up to his feet. “Now,” he said. “you’d better meet my wife. She is the one who really runs this school.”

While I was waiting to go into university, I saw in a newspaper a teaching job wanted at a school about ten miles from where I【小题1】. Because I was in great need of  【小题2】and wanted to do something useful, I applied(申请).
Three days later, a letter【小题3】. It asked me to see the【小题4】at Croydon. It proved to be a (n) 【小题5】journey —a train to Croydon station, a ten-minute bus ride and then a walk of【小题6】a quarter of a mile. As a result I arrived there, feeling too hot to be nervous. Clearly, the principal【小题7】opened the door. He was【小题8】and round.
“The school” he said, “has a group of twenty-four boys between seven and thirteen.”
I should have to teach all the 【小题9】except art, which he taught himself. I should have to divide the class into 【小题10】groups and teach them at three different  【小题11】, and I was not【小题12】at the thought of teaching maths —a subject which I didn’t do very well in at school. It was 【小题13】that I had to teach them on Saturday afternoon 【小题14】most of my friends would be 【小题15】themselves at that time.
Before I had time to ask about my salary(薪水), he got up to his feet. “Now,” he said. “You’d better meet my wife. She is the one who really runs this school.”