Venice is known as"( )"London is known as"(

Venice is known as"( )"London is known as"( as is known to. AS IS KNOWN TO ALL as is known,it is known不同用法? As is known 还是It is known英语 He is little known as an artist. As is known（在句首时） as is known to all的意思 is known as the city of sonw welcome to the London Underground,or as it is commonly known as it is known to all与as is known to all与it is known to all as is known to all中的as是什么词性