here are four basic _____ of blood inthe human body. What do you belong to, A, B, AB or O

Have you heard of the singer and actor Lin Zhiying—Yes, of course. He is______ unusual car racer, too.

offered us a lift when he was leaving theoffice, but our work ______, we didn’t accept the offer

You ________ South Africa. Can you _________ English

Who is the person talking with you just now? — Well, if you ______ know, his name is David.