Question

【题目】They have waited for three ________ before going back to see the professor. (month)

Answer 1

【答案】months

【解析】

句意：他们在回去见教授之前已经等了三个月。

根据“for three”可知表示的是一段时间，用可数名词month的复数形式months。故答案为months。