一个主意的英文怎么写

　　他正准备关门，突然想到一个主意。

　　He was about to shut the door when an idea came to him

　　别问我为什么他们一会儿一个主意。

　　Don't ask me why they have chopped and changed so much.

　　他刚刚想到一个主意。

　　An idea has just come into his mind.

　　我们的思想集中在一个主意上。

　　Our thoughts centre upon one idea.

　　我们出发之前打个电话是个好主意。

　　It would be a good idea to call before we leave.