The police still haven’t found her, but they’re doing all they      .

— Who’s singing in the next room?— It ____ be her . She has gone to New York.

—This pair of shoes ____ belong to Jack. He likes this kind very much.—It ____ be his. It’s too large for him.

You may get lost easily in big cities like Beijing        you have a map or a guide.

—How dangerous it was!—Yes, but for the passer-by’s quick action, the girl ________.