—Could I play computer games for a while, Mum? I’ve finished all my homework. —Oh, dear, if you _____.

 —You know that you were driving at 100 kilometers per hour, don’t you?—No, officer, I _____ have been. This car can’t do more than 80.

If only I _______ more confidence in the English speech contest held last week!

I can''t think he ____ tell me a lie . 

Perce Blackborow and his companions stayed on Elephant Island for six months before rescue came, so they ________ a lot of difficulties.