The reason ______ the delay is ______ we have had difficulty in obtaining materials.

We must act now because time is _____. —Yes. Let’s start.

_____ do you learn English? — By listening to tapes and reading aloud．

May I speak to the headmaster?—He’s not here．He _______ Beijing．Can I take a message?

Who’s your Chinese teacher?–Miss Zhang. She has taught ______ Chinese for two years.