33. When a student asks_________it is worth staying up doing their lessons, a teacher may find it difficult to answer.
He knows little of mathematics, of chemistry.
Discovering consists of seeing what everybody has seen andwhat nobody has thought.
—Did the policeman let you in?—No, I told him who I was.
He likesmusic so much that I think it right to buy himMP3 asbirthday present.
I suggested not only _____ go to the meeting but also give a speech there.