21. In most western countries on April Fool’s Day£¬people often play __________trick on each other£»children especially have ________ great fun.

A£®a£»a     B£®the£»the     C£®/£»a     D£®a£»/

22. Sir£¬you are not allowed to enter the building if you don’t get our manager’s __________.

A. permission     B. connection     C. instruction     D. introduction

23. During the busiest season like National Day, Spring Festival, the traffic company provides____ buses for the travelers.

A. various            B. religious     C. extra               D. raw

24. —Are you familiar __________ the customs?

—No. The place isn’t familiar __________ me.

A. with£»with   B. to£»to   C. to£»with    D. with£»to

25. In order to find a cure to the disease H1N1 flu, they _______ information about little-known disease.