— 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
网友回答
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。