— Mr. Wang, I got zero on Answering Sheet One. Could you help me correct it?— I’m sorry, but it ______ be marked by the machine. Mark your test number with a pencil 2B next time.

—Who’s that over there, Is it Jane?—No, It ________ be Jane. She is ill in hospital today.

Whale beachings（搁浅）_______ be caused by factors such as illness, or disorientation（迷失方向）caused by extra noise in the oceans, ______ shipping or oil and gas drilling.

Last year I _________ drive. I used to take the bus.

Mr. Smith has promised that all of us will pass the exam, so it ____ so difficult as you imagine.