单选题
Research findings show we spend about two hours dreaming every night,no matter what we（ ）during the day.
Ashould have done
Bwould have done
Cmay have done
Dmust have done
正确答案
答案解析
该题考查情态动词用法。本题包含宾语从句，从句的谓语动词为陈述句语气，因此可将表示虚拟语气的A、B选项排除,must have done表示对过去肯定推测不合题意，故答案为C。