Well, we enter when the ray hits the flat face, when we hit the plane.

当射线击中这个平面，就进入了区域。

youdao

Physically, they often have a flat face with a short neck and smaller hands and feet.

常为平脸、短颈、手和脚较短。

youdao

Well, for a hemisphere we would need to add maybe the flat face of a bottom or something like that.

对于半球我们需要加,一个平的底面之类的边界。

youdao

At first,Andrea Nemethi's face wasn't flat enough for glasses.

VOA: standard.2010.06.30

This is because the new fossil and 1470 share several features, including the flat face below the nose and dental structure, which once led to the species' separation.

BBC: Fossil key to human origins

However, Dr Reich points out, if humans and chimpanzees had undergone an initial separation at this time, it could account for why the skull has human-like features, including a relatively flat face without a protruding snout.

ECONOMIST: Humans could have interbred with chimpanzees

The fact is that today, Facebook at its core, is flat on its face in the mobile world.

FORBES: Facebook Phone Rumors - Social Mobility Is Big Business