试题题干
Fill in the blanks with the words given in brackets. Make changes or add something where necessary.
When I returned home last evening, he had already fallen asleep. He must
(take) sleeping pills.
参考答案
试题解析
由题干可知前一句话的意思是后一句的原因，或语境。后一句话是根据前一句话推测的结果，因此应当用must have done 来表推测。句意：昨晚我回家的时候，他已经睡着了，他一定是吃了安眠药。