The professor warned the students that on no account _____________ use mobile phones in his class.
should they
they should
dare they
they dare
I didn’t know his telephone number, otherwise I him.
-- How was your trip to London ? -- Great. I was helped by an organization. Otherwise, I _____ it.
I didn’t know that he was a cheat, or else I ________________ him.
If he had spent more time practicing speaking English before, he _____ able to speak it much better now.
They must have been enjoying themselves there,or they __________ so long.