When _________ for a certain job, you have to go through all the newspapers to look for information.
_______ my teachers’ help, I wouldn’t have succeeded.
Not until _______ 18 years old _______ a right to vote.
--Who is the person talking with you just now? -- Well, if you ______ know, his name is David.
Alice, _______ university teacher from Australia, teaches me ______ English in her spare time.
It is morning _____ we have four classes, not afternoon.