-I called you at 10:00 p.m.last night, but nobody answered the telephone.? -Oh,

—I called you at 10:00 p.m.last night, but nobody answered the telephone.?

—Oh, that was probably _______ I was out to take a walk.?

A. why B. what?

C. that D. when?

试题答案

D?

解析:

根据上句的意思，下句的意思是“那时候我可能出去散步去了”，所以用when引导表语从句。