.If ,the experiment will be successful.
A. carefully doing
B. it done carefully
C. carefully done
D. doing carefully
网友回答
A. carefully doing
B. it done carefully
(答案→)C. carefully done
D. doing carefully
解析：考查状语从句的省略。主语the experiment与do之间是被动关系，所以用过去分词done，句意：如果这个实验被认真做的话，它会成功的。carefully done前省略了it is，所以选C。