Question

This approach, ______ more expensive than the basic one, provides us with considerably more usage flexibility.

1. A.
   as
2. B.
   since
3. C.
   while
4. D.
   if

Answer 1

C
试题分析：考查连词。A.as因为，一边．．．一边，尽管（要用倒装）B. since既然，自从．．．以来C.ｗhile当．．．时候，尽管D.if如果。句意：这种方法，尽管比基本方法更昂贵，但我们提供了更多的使用灵活性。故选Ｃ
考点：考查连词。
点评：不同的连词要放在上下文中进行考查，要注意一词多义，如本题中as ，while均有“尽管”之意，但as要用倒装，while不能用倒装。
即学即练：We need some more facts and figures __________ we take the final decision.
A. since           B. before             C. after            D. until
选B