The doctor will not perform the operation ___ it is absolutely necessary

We should devote all our time ________ poor people.

Look at the timetable. Hurry up! Flight9598 ______ off at 12:18.

My uncle isn’t _____ at the moment.

Shall I pick up your shopping for you? — Oh, I couldn’t possibly trouble you — It’s all rightI _________ past the shop anyway