The app works best when your phone is resting on a flat surface, like a table.

该应用程序在手机搁在桌子之类的平面上效果最佳。

youdao

Place a towel underneath the item on a flat surface, and cover it with paper towels.

将衣物铺在平整的表面上，下面放一块毛巾，然后用纸巾盖住。

youdao

Keep the barbecue pit on a flat surface in an open area. Be sure your outdoor fire extinguisher is close to your barbecue pit.

所以请在一个宽阔的平地上做烧烤，并确保周围有灭火器。

youdao

It is a small device that you move around on a flat surface in front of a computer.

VOA: special.2010.08.01

"Well,one of the things that's interesting about these flexible sheets is that they can be curved, so you could imagine putting them in unconventional forms, like on the surface of a vehicle or something like that, where you don't have a flat surface."

VOA: standard.2010.02.19

Before, 50-year-old Trevor Prideaux had to balance the phone on his arm or put it on a flat surface.

FORBES: Man Installs Nokia Phone In His Prosthetic Arm

When placed on a flat surface, the stack redirects the waves such that reflected waves are exactly as they would be if the stack were not there at all.

BBC: Acoustic 'cloaking device' shields objects from sound

Because peregrine falcons don't build nests but lay their eggs on a flat surface, officials with the Port Authority of New York and New Jersey started protecting the eggs several years ago by building nesting boxes on the George Washington and the other bridges the authority operates.

WSJ: 4 falcon chicks living on NY-NJ bridge are banded