be known as； be known for； be known to； be known in
be known as 意为“作为……而著名”，其后的名词表示一个人的身份、职业等。如：
Liu Huan is known as a singer．刘欢作为一个歌手而出名。
We’re sure you’ll be well-known as an artist．我们相信你会成为一位著名的画家。
be known for 意为“因……而著名”，其后所接内容表示某人或物的特点、特长等。如：
Guilin is known for her beautiful mountains and rivers．桂林因其美丽的山水而闻名。
Mr Geldof is well-known for organizing two big pop concerts on the same day．
盖尔多夫先生因在同一天组织两场大型的流行音乐会而出名。
be known to “为……所了解／知道”，其后接表示人的词语。“（人们都）知道”，其后接动词原形。如：
He is known to all in our village．村子里的人都了解他。
He was known to have invented many things．＝It was known that he had invented many things．
人们都知道他已经发明了很多东西。
be known in 意为“在某地很著名”。如：
He is well-known in the town where he was born． 他在自己出生的那个镇子上很出名。
