大全－11－15

zxzhyzcy

可以请问一下吗

既然the sentence tells us that the drop of lead contamination is neither due to the decline in industrial discharges nor the regulation of the government.
    

那么两者都不是原因，并没有支持结论啊~迷惑中~

感觉B也就是在排除了政府措施这个原因的基础上强加了一个正确答案……同意jandjshi~~

raikey

没看清楚,错选了E.不过我认为B也是有问题的,纯粹是因为其他选项更离谱才选B.

看B:Most of the decline in industrial discharges of lead occurred before 1976, but the largest decline in the level of river contamination occurred between 1980 and 1985.

而题目要求加强的结论是the major cause of the decline was a 75 percent drop in the use of leaded gasoline between 1975 and 1985.

largest不等同于major, 百分比最大才能叫major.

smartsky11

二厅

yj79434175

还是没有懂。。。。哪位大侠来帮帮忙。。