I will lend you the money ____ you pay it back in one month.

The girl _______ 16 years old next week.

How does your father learn Chinese, Jim? —He learns it _____ listening to the radio.[ ]

Did you see a man in black pass by just now?—No, sir. I ______ a newspaper.

A: Listen! Is it Linda singing in the next room? B: No, it __________ be her. She is still in Shanghai.