__is known to us all is that the old scientist, for___life was hard in the past,still works very hard in the past, still

问题描述:

__is known to us all is that the old scientist, for___life was hard in the past,still works very hard in the past, still works very hard in his eighties.
A. It; whoseB. As, whomC What , whom D. as ;whose

C
前面是what 引导的主语从句;后面是for whom引导的定语从句,原型为sth is + adj for sb.