I’m afraid he is more of a talker than a doer which is he never finishes anything.A. tha

问题补充：

I’m afraid he is more of a talker than a doer, which is he never finishes anything.

A. that

B. when

C. where

D. why

答案：

A. that

B. when

C. where

(答案→)D. why

解析：句意：恐怕他是一个说大话的人，这正是为什么他从未做成事情的原因。Which引导的是非限制性定语从句，从句中is后面是表语从句，根据句意可知D正确。