21. Your iPod is quite nice. Where did you buy ______? I want to boy ______, too.

A. one; one       B. it; it           C. it; one       D. one; it

22. You know Animal World is on TV ______ 6:30 p.m. ______ 7:00 p.m.

    A. from; to       B. between; to     C. from; and     D. at; at

23. He is listening to the music ______she is washing clothes.

    A. after          B. as            C. when         D. while

24. I am sure ______he will come here tomorrow. But I doubt ______he will help you or not.

    A. that; if        B. that; whether    C. if; that       D. if; whether