cover,遮盖。

Mary covered her face with her hands. 玛丽用双手捂住脸。

cover,有涵盖的意思，下面这句子表示抵消。

The price just covers the cost． 这个价格正好抵消成本。
His report covered many subjects． 他的报告涉及很多课题。

cover,采访，报导。

Jack covered the Gulf war for CNN.杰克当时替美国有线新闻电视网报导海湾战争。
cover做名词可表示封面。
Don't judge a book by its cover.不要用书的封面来判断一本书，引伸的意思是不要以貌取人。