The invention of the modern computer is one of the greatest contributions ___to man's efficiency
问题描述：
The invention of the modern computer is one of the greatest contributions ___to man's efficiency
A.having ever been made
B.ever making
C.ever made
D.having ever made
答
C
这里选填的语句应该作为contributions宾语补足语,而contributions与make的关系是被动,所以应该填C