Zhao Benshan，whose overwork      his health failure last year，failed to perform in the Spring Festival

Gala on CCTV. [ ]

A. submitted to    

B. admitted to    

C. contributed to    

D. subscribed to

河流的袭夺现象是由（）作用造成的。

A.下蚀

B.溯源侵蚀

C.侧蚀

D.河流的摆动