In much of the animal world, night is the time ______ for sleep—pure and simple.

I thought that maybe my words will play a role, but when I_______ her to give up smoking, I failed. 

I don’t have to do it and _________ do you. We’re both too busy.

The little boy wishes to be ___.

 --- My son is learning English. What dictionary shall I buy for him? --- What about this one? It is __________ for beginners.