脸不是一平平的一张，而是有弧度的曲面，双颊是靠后的部分，因此就有阴影。

The human face is not flat but with curves. Thecheeks are the parts bent backwards, therefore are shaded.

youdao

脸不是一平平的一张，而是有弧度的曲面，双颊是靠后的部分，因此就有阴影。

The human face is not flat but with curves. Thecheeks are the parts bent backwards, therefore are shaded.

youdao