I won’t change my belief _________ success comes to those who act．

The problem has _____ simply because you didn’t follow the instructions in the handbook. [ ]

下列各句中，表达得体的一句是（ ）

You’d better _____ his name, address and telephone number in your notebook before you forget them.

His aunt wants to have him _______ the radio, but he has had it ______ already.