GWD TN22 Q7 语法题求大家解答

liaoyuan614

各位大侠，

马上要考了，心里紧张啊~GWD TN22 第七题语法题如下：

The soft drinkcompany’s flat earnings for the second quarter reflect the success of bothits restructured global bottling system and the extent to which poor currencyexchange rates keep down profits for multinational companies

A.   reflect both the success of its restructuredglobal bottling system and the extent of poor currency exchange rates keeping

B.   reflect both the success of its restructuredglobal bottling system and the extent to which poor currency exchange rates arekeeping

C.   reflect both the success of its restructuredglobal system and the extent of poor currency exchange rates keeping

D.   both reflect the success of its restructuredglobal bottling system and to what extant poor currency exchange rates arekeeping

E.    both reflect the success of its restructuredglobal bottling system and to what extent poor currency exchange rages arekeeping

答案是B。为什么不选C呢？C的结构也平行。同时对B还有一个疑问，为什么B会从 keep 改成are keeping，这两者表意有什么不同吗？这种更改是必须的吗？

感谢各位大侠回复！