阅读理解。

     Before 1900, many theories existed as to the cause of yellow fever (黄热病). Some doctors were sure the

disease was air-born; others felt that it was spread from person to person. Dr. Carlos Finlay, a well-known

Cuban doctor of that time, had long held the theory that it was caused by the bite of mosquitoes (蚊子). But

neither the pubic nor the doctors then accepted his idea.

     Despite this, Walter Reed, an American doctor sent to study yellow fever in Cuba, went to talk with Finlay.

Reed, after reading a lot on the subject, had begun to think that Dr. Finlay might be right. Then Reed and his

comrades set to work at once. Outside Havana, they set up a laboratory and began experiments to test the

theory. The experiments were successful. Now we know: A period of about two weeks must pass before a

mosquito, after feeding on a sick person, could infect another person. The sick person had to have yellow

fever a certain number of days before the mosquito biting him was able to carry the disease.

1. Before 1900,many people didn't think yellow fever was spread _____. [ ]

A. by air

B. by getting in touch with the patient

C. by the bite of mosquitoes

D. by dirty water

2. What is true according to the passage?

A. Reed agreed with Finlay after his talk with him.

B. Reed proved the theory by reading a lot of articles.

C. Reed proved the theory in his American lab.

D. Reed scientifically proved the theory.

3. Who first realized the actual cause? [ ]

A. The public.

B. Reed.

C. Finlay

D. Doctors

4. A person comes down with yellow fever because he has been bitten _____. [ ]

A. by a mosquito

B. by a mosquito that has bitten a patient

C. by an infected mosquito

D. by a mosquito that has bitten a patient of some days

5. What is the possible title of the passage? [ ]

A. Reed, an Outstanding Doctor

B. Several Theories on Yellow Fever

C. Fight Against Yellow Fever

D. The Cause of Yellow Fever