Their faces were blackened with soot.是什么意思？

Their faces were blackened with soot.

他们满脸煤灰。

their

pron. 他（她，它）们的，在提及性别不详的人时，用以代替 him 或 her；

例句
Their permissiveness toward their children reflects the wild abandon of their own lives.
他们对孩子的放任折射出他们自身生活的放浪形骸。

faces

n. 面容( face的名词复数 )，表面，脸，方面；v. 面对( face的第三人称单数 )，面向…，正视，承认；

例句
Smiles, nods, and cheerful faces added to the general gaiety.
微笑、点头和喜洋洋的脸庞使喜庆的气氛变得更浓了。

were

be的过去时复数和第二人称单数形式，有时代替 was,用于条件从句、动词 wish 之后等；

例句
Shops, houses, and vehicles were set ablaze.
店铺、房子和车辆全都陷于火海。

blackened

adj. （食品）涂上辣椒粉和调味品后油炸的，熏制的；v. （使）变黑，把…弄黑( blacken的过去式和过去分词 )，发暗，败坏（名誉等），诋毁；

例句
... a wall blackened by soot.
被煤烟熏黑的墙壁

with

prep. 和，跟，随着，关于，和…一致；

例句
A waiter entered with a tray...
侍者端着托盘进来了。

soot

n. 煤烟，烟灰，油烟；v. 煤烟弄脏，弄得尽是煤烟；

例句
The parks and squares looked grim under a mantle of soot and ash.
在一层烟尘的笼罩之下，公园和广场显得阴沉沉的。