GWD-9-12

lindazhou

GWD-9-Q12:

A mosquito bite can transmit to a person the parasite that causes malaria, and the use of mosquito nets over children’s beds can significantly reduce the incidence of malarial infection for children in areas where malaria is common. Yet public health

officials are reluctant to recommend the use of mosquito nets over children’s beds in such areas.

Which of the following, if true, would provide the strongest grounds for the public health officials’ reluctance?

A.   Early exposure to malaria increases the body’s resistance to it and results in a lesser likelihood of severe life-threatening episodes of malaria.

B.    Mosquito bites can transmit to people diseases other than malaria.

C.   Mosquito nets provide protection from some insect pests other than mosquitoes.

D.   Although there are vaccines available for many childhood diseases, no vaccine has been developed that is effective against malaria.

e.The pesticides that are most effective against mosquitoes in regions where malaria is common have significant detrimental effects on human health.

why is the answer A, not C?

[此贴子已经被作者于2005-9-10 15:45:12编辑过]

lisony

顶，同问

Winterfish

当然A啦

cissy1987

C项我觉得跟题目无关，因为c项表达的是mosquito nets可以保护人免受除了mosquito以外其他的insect pests。但是这个并不能说明health officials 不愿意推荐mosquito nets的原因。

a项说是因为早期患有malaria可以增强身体抵抗力然后减少之后人生出现malaria危险的几率。

所以应该选a