请选择ABCD't1H2W9v,qGreat as Newton was, many of his ideas ___________ today and are being modified by the work of scientists of our time.'w4H/}6|7a:e-?4N+?6k
A. are to challenge'w4H/}6|7a:e-?4N+?6k
C. have been challenged'w4H/}6|7a:e-?4N+?6k
B. may be challenged'w4H/}6|7a:e-?4N+?6k
D. are challenging'w4H/}6|7a:e-?4N+?6k