hide和conceal的区别?

据answers.com这二个字没有多大的区别：Hide and conceal are the most general and are often used interchangeably:
例句：
I used a throw rug to hide (or conceal) the stain on the carpet.
I smiled to hide (or conceal) my hurt feelings.
参见：
另外,其他网上讨论的结果也是二者没有多大区别.