Before a problem can be solved, it must be obvious ______ the problem itself is. A. what B that C which D why
______ in a big and crowded department store, poor Jack burst out ______.
_______ by the police, the kidnappers had nothing to do but ______ up.
He walked up and down the room for half an hour, _______ behind him.
Being in a foreign country, _______.
After seeing the play, ______.