问题
选择题
________ is known to us all is that the old worker, for _______ life was hard in the past, still works hard in his seventies.
A．As; whom
B．What; whose
C．It; whose
D．What; whom
答案
答案：D
题目分析：考查名词性从句和非限制性定语从句。As引导非限制性定语从句放句首时，后常有逗号与主句分开，is known to us all后无逗号，排除A；it作形式主语的句型是it is known to us all that...，句中that前有is，排除C；主语从句缺少主语，用what，构成what ... is that...句型。非限制性定语从句中的life是主语，即life was hard for the old worker。用whose的话，for whose life是介词短语，从句缺少主语。故选D。