What we all know is that the old scientist, _______ life was hard in the past, still works very hard in his eighties.

A．for whom

B．for him

C．for whose

D．for which

完全背书和空白背书的主要区别是（）。

A.是否在提单背面写明受让人的姓名

B.是否在提单背面写明指示人的姓名

C.背书人是否在提单背面签名

D.以上都不对