known是形容词词性
例句
1.
Diamonds are the hardest known mineral.
钻石是已知的最坚硬的矿石。
2.
It must be stated that this illness is one of the most complex conditions known to man.
必须声明，这种疾病是人类已知的最为复杂的疾病之一。
3.
She is best known for her work on the human brain.
她在对人脑的研究方面最为知名。
