凹

yī gè rén de shǒu zhǎng shì wēi āo de

一个人的手掌是微凹的。

The palm of one's hand is slightly concave.

yǒu xiē píng miàn bù fen dōu shì āo xíng duō biān xíng de duō miàn tǐ

有些平面部分都是凹型多边形的多面体。

A polyhedron some of whose plane sections are concave polygons.

dēng shān zì xíng chē hěn shì hé yǒu xiē wēi āo de chéng shì jiē dào

登山自行车很适合有些微凹的城市街道。

Mountain Bikes are great for slightly sunken city streets.

lù miàn āo tū bù píng

路面凹凸不平。

The road surface is uneven.

qiáng bì āo jìn qù le yī kuài

墙壁凹进去了一块。

A part of the wall has sunk in.

tā de yǎn jing āo xia qu le

他的眼睛凹下去了。

His eyes have sunk in.