include：只能当动词使用，表示包含。

cover：除了当动词，还可以当形容词，表示.封面，封皮；盖子；掩蔽物;幌子，借口

I've got three days' holiday including New Year's Day.

包括元旦在内我有三天假。

It's 7.50, not including tax.

共计7.50英镑，不含税款。

She covered the food with a piece of cloth.

她用布把食物遮盖起来。

Get everything in writing in order to cover your back.

一切都要立字为据，以绝后患。