An envelope is a flat paper container used to send a letter.

信封是一种扁平的容纳物，用来送信的。

youdao

Think about the difference between a flat paper map and a spherical globe.

试想下平面地图和球形地球之间的区别。

youdao

Welcome to English in a minute. An envelope is a flat paper container used to send a letter.

欢迎来到一分钟英语。信封是一种扁平的容纳物，用来送信的。

youdao

Xerox is experimenting with its own conductive inks for making electronic paper and circuitry for flat screen monitors and billboards.

FORBES: Touchy Circuits

Yet it is not certain that public journalism commands the public's interest: the Dayton paper's circulation is flat.

ECONOMIST: American democracy: Building the perfect citizen | The

That office paper usage will continue to be flat or slightly decline, with larger forces like the economy having more impact than mobile.

FORBES: Dreaming Of The Paperless Office? Mobile Isn't Your Savior