问题补充:
The first decade in the 21st century the rapid rise of China as a world economic power.
A. witness
B. has witnessed
C. will witness
D. have witnessed
答案:
A. witness
(答案→)B. has witnessed
C. will witness
D. have witnessed
解析:本题考查时态。根据句意:21世纪的前十年已经见证了作为世界经济强国中国迅速的发展。此处用现在完成时。主语是单数,故用has。