— Do you have any plan for this summer vacation Mary?— Sure I’ d like to be a volunteer

问题补充：

— Do you have any plan for this summer vacation, Mary?

— Sure, I’ d like to be a volunteer and help to the Central Park.

A. put up

B. call up

C. clean up

D. cheer up

答案：

A. put up

B. call up

(答案→)C. clean up

D. cheer up

解析：考查词组。put up张贴，举起：call up 打电话；clean up 清理，cheer up 使兴奋；这里句意：我想成为一名志愿者帮助清理中心公园。