Last night Dad and Mum didn’t come back home I finished my homework.A. whileB. ifC. until

问题补充：

Last night Dad and Mum didn’t come back home I finished my homework.

A. while

B. if

C. until

D. and

答案：

A. while

B. if

(答案→)C. until

D. and

解析：本题的含义是昨天晚上直到我完成我的作业我的爸爸和妈妈才回家，not……until……表示直到……才……的意思，符合本题，故本题选C。