21.Only thirty per cent of ______ parents say that they know what their children like to do after _____ school.
A. /, the B. a ,the C. the, / D. a, a
22. ---What do you ______ the waste bottles?
---We can sell them instead of throwing them away.
A. deal with B. to deal with C. do with D. to do with
23. Nowadays online games _______ teenagers.
A. is popular of B. is popular among
C. are popular of D. are popular among
24. My cousin is a person __________ I can discuss my problems.
A. with whom B. who C. whom D. that
