Second, we make a very conservative assumption that we are looking for a life form that is pretty well like us, since if it differs radically from us we may well not recognise it as a life form, quite apart from whether we are able to communicate with it.

　　【句子主干】

　　We make a very conservative assumption(that…), since if…, we may well not…

　　【结构分析】

　　assumption(that…), that 引导同位语从句，修饰assumption

　　a life form (that…), that 引导定语从句，修饰a life form

　　since 引导原因状语从句，修饰前面整个句子

　　if 引导条件状语从句，修饰we may well not…

　　apart from 介词结构，修饰we may well not…

　　【重点词汇】

　　conservative adj.保守的;谨慎的

　　assumption n.假定

　　radically adv.根本地

　　apart from 除……外(别无);除……外(尚有)

　　【句子翻译】

　　第二，我们保守地假定在寻找和我们人类极其相似的生命形式，如果形式完全不同，那我们可能并不会识别出，更不用说是否能与其交流。

　　翻译练习

　　中翻英：

　　1. 除了不能大吃甜食之外，她生活地很开心。

　　2. 除了难得偶尔来看看我们，他再没来和我们住在一起。

　　英翻中：

　　However, when we look at the 100 billion stars in our galaxy (the Milky Way), and 100 billion galaxies in the observable Universe, it seems inconceivable that at least one of these planets does not have a life form on it; in fact, the best educated guess we can make, using the little that we do not know about the conditions for carbon-based life, leads us to estimate that perhaps one in 100,000 stars might have a life-bearing planet orbiting it.

　　翻译答案

　　1.She was happy apart from the fact that she could not gorge herself constantly with enormous desserts.

　　2. Apart from some rare and fugitive visits, he did not live with us again.