Question

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

A. that 

B. when

C. where 

D. why

Answer 1

D解析：句意：恐怕他說的比做的多，這就是他一事無成的原因。此處考查系動詞be后的表語從句的引導詞，根據句意，D項正確。