—Have you found out the telephone number I need？
—Yes，but ，I have sit here for nearly a half hour.
A. for finding it out
B. to find it out
C. for finding out it
D. to find out it
网友回答
A. for finding it out
(答案→)B. to find it out
C. for finding out it
D. to find out it
解析：从句中上下文看，空白处填一个表目的的不定式才符合句意，for加动名词不能表目的，故A、C两项不对。D项不合语法。