问题
选择题
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
答案
答案：B
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。