单选题 Research findings show we spend about two hours dreaming every night, no matter what we ______ during the day.
A. must have done B. would have done
C. should have done D. may have done

【正确答案】 D

【答案解析】[解析] may have done sth. 意为“可能做了某事”。must have done sth. 表示推测，作“肯定做了某事”讲。would have done sth. 意为“本来可能做了某事”。should have done sth. 作“本来应该做某事(而实际未做)”讲。