A. pick up                    
B. set aside    
C. put off                    
D. give away

A. a                            
B. the      
C. /                            
D. an

     It is interesting how NASA (美国航空航天管理局) chose their astronauts (宇航员)
for landing them on the moon. They chose men__1__ the age of twenty and thirty-five. There
were about fifty of them. Many were__2___air pilots.__3__were scientists with two
or three degrees. NASA telephoned each man they were going to choose, told them the
plans and the__4__they might get in. They then asked him if he was willingto be trained
as an astronaut. "How could any man__5__such an exciting job?" one of them said.
"Dangerous? Of course, it's dangerous,__6__most exciting! "
     The health and physical condition of __7__was, of course, very necessary.__8__those in
very good health and physical condition were chosen.
     While being trained to be astronauts, they went through many__9__. They studied the
stars and the moon, and they also studied geology, the science of rocks. This was
necessary__10__astronauts would have to look for rocks on the moon. They would try to
find rocks which might help to tell the__11__of the moon. They were all__12__to fly in
helicopters. These helicopters landed__13__down to give them some experience of the
way the spaceship would.__14__land on the moon. They were also taught all the__15__
facts about the conditions. They learnt all the technical details of the spaceships and
rockets. They visited the scientists and engineers who__16__them. They visited the
factories where they were__17__.They learnt how every__18__of a spaceship and
its instruments work. They also learnt every detail of ground-control__19___.
     In a word, to be chosen as an astronaut, one must be in good health,__20__in
science and good at piloting.

     Edmund Halley was an English scientist who lived over 200 years ago. He studied the
observations of comets(彗星) which other scientists had made. The orbit of one
particular comet was a very difficult mathematical problem. He could not figure it out.
Neither could other scientists who dealt with such problems.
However, Halley had a friend named Isaac Newton, who was a brilliant mathematician. 
Newton thought he had already worked out that problem, but he could not find the
paper on which he had done it. He told Halley that the orbit of a comet had the shape
of an ellipse(椭圆形).
     Now Halley set to work. He figured out(觯决,计算出) the orbits of some of the
comets that had been observed by scientists. He made a surprising discovery. The
comets that had appeared in the years 1531, 1607 and 1682 all had the same orbit.
Yet their appearances had been 75 to 76 years apart.
     This seemed very strange to Halley. Three different comets followed the same orbit.
The more Halley thought about it, the more he thought that there had not been three
different comets, as people thought. He decided that they had simply seen the same
comet three times. The comet had gone away and had come back again.
     It was an astonislung idea! Halley felt certain enough to make a prediction(顶言 )
of what would happen in the future. He decided that this comet would appear in the
year 1758. There were 53 years to go before Halley's prediction could be tested.
     In 1758 the comet appeared in the sky. Halley did not see it, for he had died some
years before. Ever since then that comet had been called Halley's comet, in his honour.

     Michael a typical American, stays home on workdays. He plugs into his personal
computer terminal in order to connect with the office. After work he puts on his
headphones, watches a movie on his home video recorder or plays baseball on the
computer. On many days, michael doesn't talk to any other human beings, and he
doesn't see any people except the ones on television. Michael is imaginary, but his
lifestyle is very possible. The inventions of modern technology seem to be cutting
US off from contact with our fellow human being
     The world of business is one area which technology is isolating. US experts say,
for example, that many people will soon be able to work at home. With access(接通)
to a large central computer, employees such as office clerks, insurance agents and
accountants could do their jobs at display terminals in their own homes. They would
never have to actually see the people they're dealing with. In addition, the way
employees are paid will change. Workers' salaries will be automatically paid into
their bankaccounts (账户 ) , makingpaper checks unnecessary. No workers will
stand in line to receive their pay or cash their checks. Personal banking will change,
too. Customers will deal with machines to put in or take out money from their accounts.
     Another area that technology is changing is entertainment. Music,for instance,was
once a group experience. People listened to music at concert halls or in small social
gatherings. For many people now however, music is an individual experience. Walking
along the street or sitting in their living rooms, they wear headphones to build a wall
of music around them. Movie entertainment is changing, too. Movies used to be social
events. Now, fewer people are going out to see a movie. Many more are choosing to
wait for a film to appear on television or are borrowing videotapes to watch at home.
Instead of laughing with others, viewers watch movies in their own living rooms.