纠结很久的两道题，诚向各位高手求救

加油懒猫

有几道题一直不太确定答案，还望各位高手牛人指点指点，小的不胜感激！

1  One of every two new businesses fail within two years.

A fail

B fails

C should fail

D may have failed

E has failed

本题选B，答案说因为主语是单数。但语法书上说的是当强调the one时，谓语为单数形式。到底哪个对？

2    Some biographers have not only disputed the common notion that Edgar Allan Poe drank to excess but also questioned whether he drank at all.

A have not only disputed the common notion that Edgar Allan oe drank to excess but questioned whether he drank

B not only have disputed the common notion that Edgar   Allan oe  drank to excess but also over whether he drank

C have disputed not only the common notion that  Edgar Allan oe drank to excess but also whether he may not have drunk

D not only have disputed the common notion that Edgar   Allan oe  drank to excess but also questioned whether or not  he had drunk

E have disputed the common notion not only that Edgar Allan Poe drank to excess but also questioned whether he may not have drunk

本题答案选A，我选的C，题解：C中省略了questioned，改变了原意。dispute意为：争议，不同意 question意为：质疑。请问二者不能替换？本人理解是：既有dispute，又何必再有question 

3   More and more in recent years,cities are stressing the arts as a means to greater economics development and investing millions of dollars in cultural activities, despite strained municipal budgets and fading federal supports

A to greater economic development and investing

B to greater development economically and investing

C of greater economic development and invest

D of greater development economically and invest

E for greater economic development and the investment of

本题答案A，本人选B。economic意为：经济的，经济上的；有利可图的，合算的 economical意为：节俭的，省钱的，精打细算的 economically意为：在经济上，经济地，实惠地，节俭地 题解：economical改为adv形式后，词性错误，意思随之变化。为么啊？

4   Studies of the human "sleep-wake cycle" have practical relevance for matters ranging from duty assignmentd in nuclear submarines and air-traffic control towers to the staff of shifts in 24-hour factories.

A to the staff of

B to those who staff

C to the staffing of

D and staffing

E and the staff of 

为何此处要用解释为“人员的安排”？

十万分感谢！