【题目】The headmaster wanted to know _______ at the entrance of the school.
A.who were you waiting forB.who are you waiting for
C.who you were waiting forD.who you are waiting for
在线课程【答案】C
【解析】
考查宾语从句。句意：校长想知道你在学校门口等谁。分析句子结构可知，know后加who引导的宾语从句，who在这里是连接代词，不是疑问代词，要用陈述语序，故将A和B排除；再根据主句时态wanted可知，主句用一般过去式，从句也要用相应的过去时态。故选C。