—What do you think of our plan? —It will certainly ; it is a great idea.A. turn into B. pa

问题补充：

—What do you think of our plan?

—It will certainly ; it is a great idea.

A. turn into

B. pay back

C. pay for

D. pay off

答案：

A. turn into

B. pay back

C. pay for

(答案→)D. pay off

解析：D. pay off行得通、成功、带来好结果。