This letter is addressed to him under cover to his father.

这封信是附在给他爸爸的信内寄给他的。

youdao

They managed to escape under cover of darkness.

他们设法在夜色掩护下逃跑了。

《牛津词典》

The information you requested is being forwarded to you under separate cover.

现另函寄上所要资料。

《牛津词典》

"I broke him straight away, that always makes a big difference, " added Murray about a match that was played under cover due to rain at Melbourne Park.

CNN: Nadal and Murray ease into second round

At the start of the war, the stud moved east toward Russia to escape the advancing Germans, all the horses trotting under cover of night to escape the strafing aircraft.

ECONOMIST: Horses with wings

Instead, Fitzgerald argued that Libby had lied under oath to cover up a political embarrassment.

NPR: Lewis 'Scooter' Libby Found Guilty of Lying