Terri: Derrick, don't you think you should take a vacation? Even one or two days would be fine.Derrick:__________ There's too much work.

These natural resources will be______sooner or later if the present rate of exploitation continues.

Either you or one of your students ______ to attend the meeting that is due tomorrow.

—Do you learn Russian or French?—I learn ______.

Duty is an act or a course of action that people __________you to take by social customs, law or religion.

Duty is an act or a course of action that people ______you to take by social customs, law or religion.

Don’t ______ that rope, or you might fall.

_____city do you prefer, Shanghai or London?

It will be a relief over the death of a friend or a relative if the friend or relative dies from ______.

Hurry up, or you ______ catch the train.

I think you should end it ______ it is too late, or you will be sorry for it.

Do you want to change this lamp for__________or do you want your money back?