I had to wait five minutes on the line _____________ him.

I went to the post office _____________ some stamps.

The students are to submit their final assignments by the end of this month. are to submit in this sentence shows….

You must do your homework before you can go out. The underlined words can be best replaced by________

What are you going to do if we refuse ______________ you?

The registration form needs ____________ completely by the participants.