问题

Many people can not learn any lessons from the mistakes____they get hurt somehow.

A:whether
B:unless
C:if
D:when

正确答案是：

同类题型

e careful! Don’tbreak the bottles. Do you hear _______ I said, David————Yes, mum.

Our school is so famous that ______ people come and visit it every term.

It is reported that the police will soon ______the case of two missing children

下列各句中，没有语病的一项是

You ______ stop when the traffic light is red.