单选题 Africa is the second largest continent in the world, Yet much of Africa has not been developed by man into farms and cities. One of the reasons is that a dangerous and unpleasant insect called the tsetse fly(采采蝇)is found there. This fly makes its home in the heart of Africa.
The tsetse fly is a little larger than the housefly. Its name means "fly that destroys cattle". It lives by sucking blood from animals. It attacks man, as well as his herds of cattle.
The tsetse fly carries sleeping sickness to those men it bites. Sleeping sickness makes men veryill, and some forms of it cause death. The tsetse fly also causes diseases in animals. In some places in Africa, it has destroyed whole cattle herds.
It is hard for man and his cattle to live with the tsetse fly. Some experts even think that it has kept 400 million square miles of Africa a wilderness. This wilderness is a place as large as the whole United States. Without the tsetse fly, more land could be used by man.
Without it, many more cattle could be raised. People are working to get rid of the fly. However, it is a hard job and will take a long time.

单选题 On the whole, the passage is mainly about ______.
A. the second largest continent in the world
B. a dangerous and unpleasant insect
C. farmland in the heart of Africa
D. a kind of illness that can destroy cattle
【正确答案】 B
【答案解析】[解析] 主旨题。全文主要讲述了采采蝇的分布、外形、危害、及对非洲大陆的影响等。所以B正确。
单选题 Why is the tsetse fly a problem in Africa?
A. People do not like the sound it makes.
B. It eats food that people need.
C. It has killed many cattle herds.
D. It can destroy the crop there.
【正确答案】 C
【答案解析】[解析] 推理题。文章第三段说采采蝇能致动物生病,在某些地方甚至可能摧毁整群家畜,可推知C项为答案。
单选题 Which statement does this passage lead you to believe?
A. It won't be easy to get rid of the tsetse flies in Africa.
B. Sleeping sickness is unknown to Africans.
C. People did not know sleeping sickness could cause deaths.
D. The people there did not know the tsetse carried a kind of disease to man.
【正确答案】 A
【答案解析】[解析] 细节题。文章最后一句说消灭采采蝇是一个艰巨而长期的任务。所以A正确。
单选题 Which of the following is true?
A. People have done nothing to get rid of the tsetse flies.
B. People are trying to find out ways to get rid of the tsetse flies.
C. No ways can be found to get rid of the tsetse flies.
D. It won't be long before people get rid of all the tsetse flies in Africa.
【正确答案】 B
【答案解析】[解析] 细节题。文章最后一句说人们在寻找消灭采采蝇的方法。所以选B。