[单项选择]Why could not people use stamps for many times [A] Because the stamps would be taken away when they had been used. [B] Because the stamps would be torn up (撕碎) when they had been used. [C] Because the stamps would be put on seals by the post office.

[单项选择]Why could not people use stamps for many times [A] Because the stamps would be taken away when they had been used. [B] Because the stamps would be torn up (撕碎) when they had been used. [C] Because the stamps would be put on seals by the post office.

[单项选择]Why They Came
Not many decisions could have been more difficult for a family to make them to say farewell to a community where it had lived for centuries, to abandon old ties and familiar landmarks, and to sail across dark seas to a strange land. Today, when mass communications tell one part of the world all about another, it is quite easy to understand how poverty or tyranny might force people to exchange an old nation for a new one. But centuries ago migration was a leap into the unknown. It was an enormous intellectual and emotional commitment. The forces that moved early immigrants to their great decision — the decision to leave their homes and begin an adventure filled with uncertainty, risk and hardship — must have been of overpowering proportions. As Oscar Handlin states, the early immigrants of America "would collide with unaccustomed problems, learn to understand alien ways and alien languages, manage to survive in a very foreign environment".A. searching for religious freedom
B. breaking with past cultural inheritance
C. escaping political oppression
D. searching for riches

[填空题]What do the ordinary people collect stamps for They collect stamps for ______.

[填空题]What do the ordinary people collect stamps for
They collect stamps for （）.

[填空题]Why do many companies still hesitate to use the Web to expand its market though the Web has proved to be more than a fashion today

[单项选择]How many people use the Internet in South Africa
A. 34 million.
B. 12 million.
C. 1.2 million.
D. 16 million.

[单项选择]

Many people use wood stoves and fireplaces to heat their homes. Scientists have become worried about the smoke that they give off. Harmful chemicals are in the smoke. The smoke is causing air pollution. The pieces of pollution, called soot, are floating in the air. They are too tiny to see. Scientists must use a microscope to see them.
Small amounts of soot are safe, but large amounts can be dangerous. The government wants to limit this kind of pollution. It may stop people from using their fireplaces.
The air is tested every day. When soot levels are high, more than 65 micrograms of soot per cubic meter, factories must stop making smoke. The government thinks that limit should be much lower.
Factories produce the most smoke and soot. But the government thinks that all types of burning should be limited. The soot levels from factories and homes could be limited. Home owners may have to install new wood stoves that they comply with the new law. Or, they may
A. They could lose their homes.
B. They pay for the punishment.
C. They get sick from the smoke.
D. The fire could get out of control.