.If the experiment will be successful.A. carefully doingB. it done carefullyC. carefully

问题补充：

.If ,the experiment will be successful.

A. carefully doing

B. it done carefully

C. carefully done

D. doing carefully

答案：

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。