47. According to scientists at the University of California, the pattern of changes that have occurred in human DNA over the millennia indicate the possibility that everyone alive today might be descended from a single female ancestor who lived in Africa sometime between 140,000 and 280,000 years ago.

(A) indicate the possibility that everyone alive today might be descended from a single female ancestor who

(B) indicate that everyone alive today might possibly be a descendant of a single female ancestor who had

(C) may indicate that everyone alive today has descended from a single female ancestor who had

(D) indicates that everyone alive today may be a descendant of a single female ancestor who（D）

(E) indicates that everyone alive today might be a descendant from a single female ancestor who

E选项为什么不对?请教might be与 may be的区别,谢谢!

48. According to some analysts, whatever its merits, the proposal to tax away all capital gains on short-term investments would, if enacted, have a disastrous effect on Wall Street trading and employment.

(A) its merits, the proposal to tax

(B) its merits may be, the proposal of taxing

(C) its merits as a proposal, taxing

(D) the proposal’s merits, to tax（A）

(E) the proposal’s merits are, taxing

"whatever its merits, "似乎不是一个句子啊!?

我查了牛津字典,whatever后面因该是个有谓语的句子啊!所以我选了E.

迷茫!