I insisted that the boy          his hands before having supper.

So far no life has been found outside the earth, but while some scientists are actively searching for living things in outer space, others firmly believe there ______.

You know he is not going to let us leave early if we ___ get the work done.

If he had spent more time practising speaking English before，he________able to speak it much better now.                                                   

 He asked me for this book many times. Please tell him that he _____ have it tomorrow.