When the fire broke out, Mary didn’t know _____. [ ]

His sister wanted to have him _____ the radio, but he had had it _____ already.

His words puzzled me so much that I had a hard time trying to ______ what he really meant.

We hadn’t met for 20 years, but I recognized her_____ I saw her.

od she has prepared for the party is not enough, for there are ______ people than she expected．