1.?Life, as we know, needs water and oxygen.2. Life as we know it needs water and oxygen.句1,as we know 是传统语法的非限制性定语从句;现代语法的比较状语从句。这个就不用解释了,已经讲了若干遍了。句2,as we know it 是方式状语从句。as 是从属连词,句子不缺成分。
Life, as we know, needs water and oxygen.
Life as we know it needs water and oxygen.
以上2句as用法究竟有何不同?请分析比较以上2句as的用法,指代成分,词性,语法分析方面等等,
另外,以上2句均属于定语从句还是方式状语从句或均可认为是as比较分句吗? 第二句中的it指代什么?