[填空题]Man can wear it on.

[填空题]Man can wear it on.

[单项选择]（） man can now create radioactive elements, there is nothing he can do to reduce their radioactivity.
A. As
B. Whether
C. While
D. Now that

[单项选择]Man can go on increasing his numbers at the present rate. In the next 30 years man will face a period of crisis. Some experts believe that there will be a widespread food shortage. Other experts think that this is too pessimistic, and that man can prevent things from getting worse than they are now. But remember that two-thirds of the people in the world are under-nourished or starving now.
One thing that man can do is to limit the number of babies born. The need for this is ob- vious, but it is not easy to achieve. People have to be persuaded to limit their families. ’In the countries of the population explosion, many people like big families. The parents think that this brings a bigger income for the family and ensures there will be someone in the family who will look after them in old age.
Several governments have adopted birth control policies in recent years. Among them are Japan, China, India and Egypt. In some cases the results have not been successful. Japan has been
A. a food shortage
B. a crisis
C. an overpopulation
D. a starvation

[填空题]Scientists have reason to think that a man can put up with far more radiation than 0.1 rem _________________(而不受伤害).

[单项选择]A. The man can check the book about ancient history out.
B. The book is not for reading in the library but for checking out.
C. The man should stay in the library to read the book.
D. The book is not about ancient history but about reference.

[单项选择]What is the lowest price the man can buy the machine for
A. $10,000
B. $15,000
C. $13,000