最常见的颅内血肿是

A．急性硬膜外血肿

B．急性硬膜下血肿

C．慢性硬膜下血肿

D．脑内血肿

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