21.
But the real truth is that we dont know enough to relieve global warming, and without major technological breakthroughs we cant do much about it. (2008年6月)
【分析】本句为复合句，主干为the real truth is that。that从句为is的表语，在该表语从句有两个由and连接的简单句we dont knowwarming和we cant do much about it。两个破折号之间的内容是对we cant do much about it的原因解释。
【译文】但真相是，我们对缓解全球变暖知道的还不够多，并且没有较大的技术突破我们仍将束手无策。
22.
We need economic growth unless we condemn the worlds poor to their present poverty and freeze everyone elses living standards. (2008年6月)
【分析】本句为复合句，主句为We need economic growth，从句为unless引导的条件状语从句。在从句中，we有两个由and连接的谓宾：condemnpoverty和freezestandards。
【译文】我们需要经济增长，除非我们迫使世界上的穷人继续穷困潦倒，不提高他们的生活水平。
23.
The trouble with the global warming debate is that it has become a moral problem when its really an engineering one. (2008年6月)
【分析】本句为复合句，主干为The troubleis that。that引导的表语从句that it has becomeone作is的表语，该表语从句中又包括一个由when引导的时间状语从句when its really an engineering one。
【译文】全球变暖的争论很伤脑筋的地方在于，全球变暖其实是一个技术问题，但在现在的争论中已经变成了一个道德问题。
24.
Whoever it is, they will see you in a way you never intended to be seen the 21st century equivalent of being caught naked. (2008年6月)
【分析】本句为复合句，主句主干为they will see you，从句为Whoever引导的让步状语从句Whoever it is。in a way为see you的方式状语。you never intended to be seen为省略了引导词的定语从句，修饰的是way。破折号在这里起解释说明的作用，解释前面的句子。
【译文】无论是谁，他们都会以一种你所不愿意被看到的方式来看你21世纪就好像是一个被人裸视的时代。
25.
Psychologists tell us boundaries are healthy, that its important to reveal yourself to friends, family and lovers in stages, at appropriate times. (2008年6月)
【分析】本句为复合句，主干为Psychologists tell us。us后接了两个宾语从句，第一个宾语从句为boundaries are healthy，省略了引导词that；第二个宾语从句为that引导的that itstimes。按照规则，若动词后跟两个由that引导的宾语从句，第一个宾语从句可省略引导词，但第二个宾语从句的引导词必须出现，不能省略。
【译文】心理学家告诉我们，隐私界线是健康的，在某些阶段，某个合适的时间，向朋友、家人和爱人展现你自己很重要。