Each of the students,working hard at his or her lessons, to go to university.
The number of people invited ______ fifty, but a number of them ______ not seen at the meeting.
A student should not ______ small errors, which might lead to serious mistakes in the future.
— ______ I’m very busy now. Could I call you back after work? —OK. I'll wait for you.
It is not right for you to ______ fifty dollars from my salary without any good reason. You should give it back to me.
—Why do you drink so much coffee? —Well, ______ it doesn't keep me awake at night, I see no harm in it.