题目内容：

Can storms in Africa cause asthma(哮喘) in the Caribbean(加勒比)? Islanders point to the desert insects that land on beaches after a 5,000-kilometer flight across the Atlantic. If they can use winds to get from one continent to another, so can clouds of dust that carry disease.

Scientists think that as Africa becomes drier, dust from expanding deserts is being blown away into Caribbean islands. A study in Barbados shows that asthma has increased 17 times since Africa’s drought(干旱) began in 1973.

Other forms of life are suffering, too. Among them are the Caribbean’s famous coral reefs( 珊瑚礁), which began dying in large numbers in the 1900s. Eugene Shinn of the U.S. Geiological Sudrvey(USGS) in Florida went to the virgin Islands to study the reefs. The tests he and his colleagues carried out showed that the coral was dying of disease caused by Africa microbes(微生物) from across the ocean.

William Sprigg of the University of Arizona is studying the problem as part of a major UN project. He says that dust is causing problems in the U.S., too.

“We are just beginning to collect the evidence of airborne(空气传播的) dust influences on human health,” he told The Washington Post.

1.Which of the following can be the best title for this passage?

A．Dangerous Dust	B．Dangerous Disease
C．Changing Weather	D．Developing Technology

2. Where does the dust talked about in this passage come from?

A．America.

B．Africa.

C．The Atlantic.

D．The Pacific.

3. The increase of asthma in the Caribean is probably related to _____ according to scientists.

A．desert insects

B．strong winds

C．airborne dust

D．dry weather

4.Which of the following is NOT true about the Caribbean coral reefs?

A．They are in Florida.

B．They used to be very beautiful.

C．They began dying in the past decades.

D．The African microbes have bad effect on them.

5. Which of the following is TRUE about William Sprigg?

A．He is a member of UN.

B．He thinks African dust also affects the US.

C．He has collected enough evidence about dust influences.

D．He is a reporter from The Washington Post.