How important is your mobile phone,better known to Americans as a cell phone?

题目

How important is your mobile phone,better known to Americans as a cell phone?
谁帮我翻译下这个句子,特别是后半句,我不知道是个什么固定词组的用法、、、
指出后半句的用法、、、不只是翻译

答案

1.你的手机,美国人更愿称它为cell phone的东西,很重要吗（cell phone和mobile phone都是手机的意思）2.be known to sb as something 是被动用法,意思是,作为某种方式为人熟知,例如,sb knows sth,变成被动就是sth is ...