Great as Newton was ,many of his ideas_today and are being modified by the work of scientists of our time
问题描述：
Great as Newton was ,many of his ideas_today and are being modified by the work of scientists of our time
A) are to challenge
B) may be challenged
C) have been challenged
D) are challenging
答
答案：C
要点：过去完成时,被动
表示牛顿的很多想法在如今已经受到很多挑战,并被当代科学家所修定.