[单项选择]Companies don' t want to spend money on research in developing appropriate crops in Africa because
A. existing technology fails to grow dry-land crops
B. only dozens of years later can they make profits
C. they are not encouraged and probably cannot make any profit
D. most of African countries belong to the third world

[单项选择]Companies don't want to spend money on research in developing appropriate crops in Africa because ______.
A. existing technology fails to grow dry-land crops
B. only dozens of years later can they make profits
C. they are not encouraged and probably cannot make any profit
D. most of African countries belong to the third world

[单项选择]

Unless we spend money to spot and prevent asteroids (小行星) now, one might crash into Earth and destroy life as we know it, say some scientists.
Asteroids are bigger versions of the meteoroids (流星) that race across the night sky. Most orbit the sun far from Earth and don’t threaten us, But there are also thousands of asteroids whose orbits put them on a collision course with Earth.
Buy $ 50 million worth of new telescopes fight now. Then spend $ 10 million a year for the next 25 years to locate most of the space rocks. By the time we spot a fatal one, the scientists say, we’ll have a way to change its Course.
Some scientists favor pushing asteroids off course with nuclear weapons. But the cost wouldn’t be cheap.
Is it worth it Two things experts consider when judging any risk are: 1 ) How likely the event is; and2) How bad the consequences ff the event occurs. Experts think an asteroid big enough to destroy lots of life might strik
A. They are heavenly bodies different in composition.
B. They are heavenly bodies similar in nature.
C. There are more asteroids than meteoroids.
D. Asteroids are more mysterious than meteoroids.

[单项选择]I don't want to lend money to him; he is already in debt __________ me.
A. to
B. for
C. of
D. with

[单项选择]I don't want to borrow the money, so I prefer to manage ______.
A. to
B. with
C. for
D. without

[单项选择]We need to spend more money on special hospitals and psyehiatrists for ______.
A. the mentally ill
B. mentally ill
C. the disabled
D. disabled

[单项选择]I don't want to lend any money to him; he's already in debt ______ me.
A. to
B. for
C. of
D. with

[单项选择]I don't want much money. Fifteen dollars ______ enough.
A. were
B. are
C. is
D. have been

[单项选择]I don't want to lend any more money to Tom; he's already in debt ______ me.
A. to
B. of
C. for
D. with

[单项选择]What does "He wisely refused to spend his money" mean

[单项选择]

Americans spend a lot of money in their daily lives. Working people spend money on transportation to and from work and on various expenses throughout the day. Americans en- joy shopping and buy many things that they need and want. They spend a lot of money on entertainment. They buy sports equipment, to do sporting events and do many things that cost money. However, many Americans don’t pay cash or write checks for these things. More and more, they pay for things with credit cards(信用卡).
Credit cards are small, rectangular plastic cards. Banks give these cards to their customers. When the customer buys something at a store, he shows his card at the store. This authorizes(委托) the store to charge(记入) the bank account for the customer’s purchase. The bank collects all the charges for each customer. Then once a month the bank requires the customer to pay all the charges for that month. The bank does not force the customer to pay the full amount. It asks the custome
A. can get what they want and need when they have no money
B. can get things at a store they cannot afford at one time
C. don’t need to carry a lot of money
D. B and C