David is such a good boy _______ all the teachers like.
-- Why do you look sad?--There are so many problems _____.
I _____ him not to smoke, but he didn’t think it necessary.
-- Could I have a word with you?-- Sorry, I am busy ________.Shall we do it later?
I tried hard to get some information about the new technology out of his mouth, but he remained .
got on the train when it began to move.