He promised to come early, but he didn’t _____ until 10 p.m.
The doctors did all they could _______ him _______.
-- You speak very good English! -- Thanks. I_______ English since I was a small boy.
_______ 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.