---Why don’t you your ideas on paper? Then you won’t forget them.Sounds a good idea.A

问题补充：

---Why don’t you your ideas on paper? Then you won’t forget them.

--- Sounds a good idea.

A. put aside

B. lay down

C. set down

D. do with

答案：

A. put aside

B. lay down

(答案→)C. set down

D. do with

解析：短语辨析。put aside撇开，扔下；lay down放下，放弃；set down写下，记下；do with对付，处理。句意：你为什么不把你的想法写在纸上？那样你就不会忘了。所以选C。