21. By tradition, on __________ Independence Day, Americans play sports, have barbecues and hold parties throughout __________ day to celebrate this festival.

A. the, the                        B. a, the                       C. the, a         D. /, the

22. It’s the __________ in the west to open a present when someone gives __________ to you.

A. custom, one                 B. habit, one          C. bobby, it    D. favour, it