The check came under cover in yesterday's mail.

支票是装在信封里和昨天的邮件一起送来的。

youdao

To cover or armor with mail.

用铠甲覆盖或武装…

youdao

With the cover of darkness, I stealthily inserted my envelope to her mail box.

趁着天黑我鬼鬼祟祟地把信封投到她家的信箱里。

youdao

We are sending you under separate cover by mail a copy of the latest catalog.

兹另发送我方最新产品目录一份。

youdao

We are sending you under separate cover by mail a copy of the latest catalog.

兹另发送我方最新产品目录一份。

youdao