When did the young man save you? —January 1st,2000, the first day of the new century,_______ I can never forget

Are you a teacher—No, but I ________.

下列各句中，没有语病的一句是

Those boys didn’t start the work ________ their teacher came back.

The audience waited until the curtain rose and then____ laughter at the sight of the funny actor.[ ]