white envelope

例句：

1. 1.The letter was enclosed in a white envelope.
   这封信被装在一只白色的信封里。
2. 2.He carefully placed the white envelope on the table.
   他小心翼翼地把那只白色的信封放在桌子上。
3. 3.She opened the white envelope to find a birthday card from her friend.
   她打开那只白色的信封，发现了一张来自朋友的生日卡片。