letter box

基本解释

He returned with the content of the letter box in his hand.
他回来了，手里拿着信箱里取出的信件。
I dropped by the post office and put my letters into the letter box.
邮局用来收集信件的信箱的号码。
JAMES MORGAN; You'll need to post a small parcel in the letter box. Have you got any change? You'll need it for stamps.
詹姆斯。摩根：你需要把小包裹放在信箱里。你有零钱吗？你需要用它买邮票。
blog.sina.com.cn

Without showing your neighbor what you are doing, put it in the box below either the letter Alpha or the letter Beta.
在不被你同桌看到的情况下,在方框中填写字母α或者字母β
耶鲁公开课 - 博弈论课程节选

Census workers are being taught, for example, to look for clues that a house has two families living in it, such as an extra letter box or electricity meter.
ECONOMIST: The politics of the census
Letter Box format is actually meant for widescreen movie theaters but a lot of people want the same aspect ratio and resolution as they see in the theaters, problem is, most of the time the master recording is in LB format.
FORBES: Linux Founder Linus Torvalds Blasts PC Industry, Praises Google's Chromebook Pixel
The stock keyboard also offers Swype-style typing and even throws in an extra bullet point for good measure: as you drag your finger from letter to letter, a box pops up showing you the word you're currently typing.
ENGADGET: Google Nexus 10 hands-on (video) Mobile

A letterbox is a rectangular hole in a door or a small box at the entrance to a building into which letters and small packages are delivered.
If something is displayed on a television or computer screen in letterbox format, it is displayed across the middle of the screen with dark bands at the top and bottom of the screen.