I just don't understand_______ that prevents so many Americans from being as happy as one might expect.
Why don’t you bring ______ to his attention that you are too busy to do it?
They live on a busy main road. ______ must be very noisy.
They are good friends. _______ is no wonder that they know each other so well.
— I don’t know whether I should go abroad or not, Mum. — I leave _______ to your own judgment whether you should do it.
Mr Ascot, headmaster of the school, refused to accept ______of the three suggestions made by the Students’ Union.