问题补充：
The boy is running impatiently here and there as if something lost on the sports ground.
A. to search
B. searching
C. searching for
D. to search for
答案：
A. to search
B. searching
(答案→)C. searching for
D. to search for
解析：“寻找” search for sth；男孩与search for为主谓关系所以用现在分词做状语。 男孩急躁的跑来跑去似乎在寻找丢在操场上的什么东西。选C
