某双代号网络计划如下图所示，工作D的总时差和自由时差分别为（）。

A．1天和1天

B．1天和2天

C．2天和1天

D．2天和2天

David, _____ I have been sharing a dorm for more than two years, is quite a funny guy.

A．of whom

B．with whom

C．in whom

D．from whom