A-A+
The lights were still on. They______ (forget)
问题详情
The lights were still on. They______ (forget) to turn them off when they left the classroom.请帮忙给出正确答案和分析，谢谢！
参考答案
正确答案：must have forgotten
must have forgotten 解析：句意：灯仍亮着。他们肯定是在走的时候忘了关。注意must have forgotten 实际上是一种极其肯定的判断形式，即情态动问must后跟have done 这种结构表判断。
