免费服务和收费服务的区别：免费服务将会生成一个带有广告的封面。

Differences between the free and paid service: the free service will generate a cover-page that includes an AD.

youdao

免费服务和收费服务的区别：免费服务将会生成一个带有广告的封面。

Differences between the free and paid service: the free service will generate a cover-page that includes an AD.

youdao