相关 relevant 填空题 GWD1-19

Q19:

Which of the following most logically completes the passage?

A certain tropical island received food donations in the form of powdered milk for distribution to its poorest residents, who were thought to be malnourished.  Subsequently, the rate of liver cancers among those islanders increased sharply.  The donated milk was probably to blame: recent laboratory research on rats has shown that rats briefly exposed to the substances aflatoxin tend to develop liver cancer when fed casein, a milk protein.  This result is relevant because _______.

1. in the tropics, peanuts, a staple of these island residents, support a mold growth that produces aflatoxin
2. the liver is more sensitive to carcinogens, of which aflatoxin may be one, than most other bodily organs
3. casein is not the only protein contained in milk
4. powdered milk is the most appropriate form in which to send milk to a tropical destination
5. the people who were given the donated milk had been screened for their ability to digest milk

这道题目的结果 蛮 surprising的，我觉得 A 很无关啊， 我差了 GWD1 一套里面， 居然没这道题目， 对不上号了

请好人帮一下吧，谢谢

真得没明白过来 

liver cancer有两个条件

1.expose to aflatoxin

2.fed milk protein

文章说进口奶粉，对应了2

如果的确时奶粉得问题话，那么得cancer还得有个条件，aflatoxin

A，说得就是条件1，当地盛产aflatoxin，再加上奶粉得捐助，使得liver cancer rate上升

哦，明白了，应该有两个条件，是并列的，我一开始把 这句话理解成了  fed casein -> aflatoxin -> cancer   。 

谢谢指点！