1.As you know, I am with my aunt and grandmother.

正如你所知道的，我是跟我姑妈和奶奶一起来的。 As you know为非限制性定语从句。 As_you_know,_there will be a speech competition on environment protection soon.

大家都知道，很快将进行一场有关环保问题的演讲比赛。 2....it is impossible to calculate what price it would fetch if it ever came on the market.

......如果这幅画在市场上出售，很难估算它的价值。 在"it is＋adj.＋to do sth."句式中，it为形式主语。 No matter how fast you run, it_is_impossible for you to_catch_up_with_him.

无论你跑得多快，你都不可能赶上他。 　　

　　1．(教材P34)He experimented with different styles of painting, but was most famous for his work in Cubism ...

　　他尝试过多种不同的绘画风格，但尤以立体派作品著称......

　　be famous for (＝ be known for) 因......而著名

　　①This actor is famous not only for his talent but also for his kindness.

　　这位演员很出名，不仅因为演技好，而且因为他心地善良。

　　be famous/known as作为......而出名(as后接表示职业、身份等的名词)

　　be known to 为......所知/熟知(介词to后接sb.)

　　②She was more famous as a writer than as a singer.

　　她作为作家比作为歌手名声更大。

　　③He is known to all in our village, for he is ready to help others.

　　我们村子里的人都知道他，因为他乐于助人。

　　[语境串记]　The young man is famous/known as a singer and he is most famous/known for singing popular songs which are known to many teenagers.

　　这个年轻人作为一名歌手而出名，他主要是因唱流行歌曲而出名的，这些歌曲为很多青少年所熟知。

　　2．(教材P34)By popular consensus, this is the most valuable painting in the world - it is impossible to calculate what price it would fetch if it ever came on the market.

举世公认，这幅画是世界上最珍贵的油画作品--如果这幅画在市场上出售，很难估算它的价值。