I think it should be called a lie because a pig is not like a day and people do not have skeletons in their cupboards.

The PAC learning framework provides a formal way to quantify the learnability of a concept class.

小规模养殖户是水产养殖的支柱，他们的知识是无价的。

我不是一件艺术品，我是一个表演艺术家。

工商业和农业一样都是国家的根本

心理现象最好从其功能角度来理解。