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?

1. Early exposure to malaria increases the body’s resistance to it and results in a lesser likelihood of severe life-threatening episodes of malaria.
2. Mosquito bites can transmit to people diseases other than malaria.
3. Mosquito nets provide protection from some insect pests other than mosquitoes.

4. Although there are vaccines available for many childhood diseases, no vaccine has been developed that is effective against malaria.
5. The pesticides that are most effective against mosquitoes in regions where malaria is common have significant detrimental effects on human health.  

the answer is A, really weird,A说得好象人一定要/会exposure to malaria，从来不感染岂不更好？

c哪里有问题？

A is right beacuse it says that getting infected in one's early years is like getting a vaccine, which is good.

C is not right. Mosquito nets of course are for protection against mosquitos, but choice C says the opposite, which is weird. The statment above already said that "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."   Hence, choice C becomes meaningless.

题目说：

蚊子咬人传播寄生虫导致一种m病。蚊帐是个好东西，能避免小孩被蚊子咬。但是卫生部门似乎不鼓励使用蚊帐

问：加强卫生部的不鼓励

A:被蚊子咬可以提高身体对m病的抵抗力，并且以后被m病威胁的可能性降低－－－加强了结果，所以一开始用蚊帐，抵抗力就从谈起了。

C：蚊帐不防蚊子，防其它害虫－－－那还是该使用蚊帐－－－反而削弱了卫生部门的reluctant；而且明明防蚊子的说不防，错

谢谢2位，以后会注意仔细看题干。