The weather turned out to be very good was more than we could expect.A. itB. that　C. whe

问题补充：

The weather turned out to be very good, was more than we could expect.

A. it

B. that

C. when

D. which

答案：

A. it

B. that

C. when

(答案→)D. which

解析：非限制性定语从句。it不能在逗号后单独引导一个句子,可以用...,and it...。when引导句子时,其前不必用逗号。that不能引导非限制性定语从句,即其前有逗号的定语从句。只有which可以引导非限制性定语从句。故选D。