二、单项选择
21. I can play ____ guitar and I can play_____ tennis, too.
A. the; the B. The; / C. a; the --What are you going to do_____ the weekend?
--_____Saturday morning I’m going to do my homework.
A.at; In B. in; On C. at; On
23. These are your_____ erasers and those are____.
A.yours; mine B. your; mine C. your; my
