Student or Learner
It's said that there are plenty of hotels in the small seaside city. So there_________ be any difficulty for you to find somewhere to stay at this moment if you want to have a trip there.
A. couldn't B. mustn't C. shouldn't D. needn't
The answer is "shouldn't". Why can't I choose A? I know "shouldn't" is right here. But I can't tell why "couldn't" is not right in case my students ask me. So please help me! Thanks!
By the way, just out of curiosity, the time in my region (China) now is pm 15:34, shouldn't it be a sleep time for Brits?