A person such kind of work must be careful enough, an eye on any sign of the possible result .
A. to do ; to keep
B. doing ; keeping
C. to do ; keeping
D. doing ; to keep
网友回答
A. to do ; to keep
(答案→)B. doing ; keeping
C. to do ; keeping
D. doing ; to keep
解析：前一空用现在分词用定语，相当一个定语从句，后一空用现在分词做状语。