--- I think it necessary that he _____ to New York but to London.
--- I agree, but the problem is _____ he has refused to.

       you be interested, I’ll tell you the whole story.

Imagine what today’s life would be like if Alexander Bell_______the telephone more than 130 years ago!

----Why does the lake smell terrible?
-----Because large quantities of water_______.

.If you are caught driving after drinking, the fine_______ be paid in cash according to the traffic rules.

. —How can I thank you?
—Don’t mention it. Any other man in that case _______ the same thing.

It ___ have been Tom that parked the car here , as he is the only one with a car.
A may    B can    C must    D should

It was playing computer games that cost the boy plenty of time that he _____have spent doing his lessons

--- I had thought he would be nervous in this speech competition, but he turned out to be calm.
--- He________quite enough preparation for it.

How______I help them to understand when they won’t listen to me?