complete the sentences with the correct time expression.  1)it'll be dark __ we get home.(while / by the time ) 2) The computer won't work __ you plug it in ! ( after / until )
3) __ it is nine  o'clock,lessons begin. ( As soon as / While)
4) Leo will have a great time __ he is in Cairo. ( by the time / while) 5) My parents will be pleased __ they get my exam results. ( when / until) 6) Elsa is going to look for a flat __ she arrives in London. ( after /while )