_______ is known to us all that the old scientist, for _______ life was hard in the past, still works hard in his eighties.?

A. It; whom?????? B. As; whose????????????? ???? C. As; whom????? ????????????? D. It; whose

_______is known to us all that the old scientist,for_____life was hard in the past,still works hard in his eighties.

A.It;whom          B.As;whom              C.As whose        D.What;whom

 _______ is known to us all that the old scientist, for _______ life was hard in the past, still works hard in his eighties.

  A. It; whom       B. As; whom      C. As; whose      D. What; whom