[求助]请教两道GMATprep题（Math和SC）

When 1000 children were inoculated with a certain vaccine, some developed inflammation炎症 at the site of the inoculation and some developed fever. How many of the children developed inflammation but not fever?

1.       880 children developed neither inflammation nor fever;

2.       20 children developed fever.

Answer：D

根据条件1，可以得出有状况的小孩共为1000-880=120个

根据条件2，
        发烧的有20个，我的问题是有没有小孩同时发烧和得炎症，如果有的话，那就求不出来只得炎症的了。从题目中看不出来，是不是发烧和炎症没有交集，碰到这种变态的题咋办？
            

A recent review of pay scales indicates that CEO’s now earn an average of 419 times more pay than blue-collar workers, compared to a ratio of 42 times in 1980.

A：that CEO’s now earn an average of 419 times more pay than blue-collar workers, compared to a ratio of 42 times

B：that, on average, CEO’s now earn 419 times the pay of blue-collar workers, a ratio that compares to 42 times

C: that, on average, CEO’s now earn 419 times the pay of blue-collar workers, as compared to 42 times their pay, the ratio

D: CEO’s who now earn on average 419 times more pay than blue-collar workers, as compared to 42 times their pay, the ratio

E: CEO’s now earning an average of 419 times the pay of blue-collar workers, compared to the ratio of 42 times

答案：
            C

为什么是C呢？好怪啊，

我选了A。
        是不是times不能和More than一起用，

B为什么不对？
        

    偶也奇怪此题。现场作题，第一步可迅速排除D和E，因为其前无THAT引导，第二步，可非除A，因为比较对象不对等，因为在A中，是now earn..和blue-collar workers比较，肯定不对。但C我也认为有问题啊，后面的their指代应该有歧义啊，应该是指代workers,但the ratio又做谁的同位语啊，B、C之间，偶也不知选谁啊，现场只有靠感觉拉！

    还请NN们，解释A、B、C中的不同之处。谢先拉！