1. This, for those as yet unaware of such a disadvantage, refers to discrimination against those whose surnames begin with a letter in the lower half of the alphabet. (2004. 阅读. Text 2)
　　【译文】但是有一种隐蔽的形式还在蔓延：按字母表顺序排名。对于尚未意识到其危害的人来说，它指的是对那些姓氏起始字母位于字母表后半部的人的歧视。
　　【析句】句子的主干是This refers to discrimination against those。其中，for those as yet unaware of such a disadvantage是插入语，those是介词for的宾语，形容词短语unaware of作those的定语；第二个those是against的宾语，后面是whose引导的定语从句修饰those。

　　2. Thus the American president and vice-president have surnames starting with B and C respectively; and 26 of George Bush’s predecessors (including his father) had surnames in the first half of the alphabet against just 16 in the second half. (2004. 阅读. Text 2)
　　【译文】如此这般，美国的总统和副总统的姓氏分别是以B和C字母起头。乔治·布什的前任有二十六位（包括其父）的姓氏均在字母表的前半部，而姓氏在字母表后半部的却仅有十六位。
　　【析句】句子的主干是the American president and vice-president have surnames...; and 26 of...predecessors had surnames。其中，and”将本句分为两个并列分句，第一个分句即“American president and vice-president have surnames”，第二个分句是“26 of…had surnames”。第一个分句的宾语“surnames”后是现在分词结构“starting with”作定语；第二个分句宾语紧跟的介词结构“in the first half of the alphabet”作定语。

　　3. Consumers seem only mildly concerned, not panicked, and many say they remain optimistic about the economy’s long-term prospects, even as they do some modest belt-tightening. (2004. 阅读. Text 3)
　　【译文】消费者看起来略显忧虑，并没有惊慌失措。许多人虽然稍微勒紧腰带，但他们说对于经济的长期前景还是乐观的。
　　【析句】先看句子主干Consumers seem only mildly concerned,and many say...。not panicked作插入语，对mildly concerned的进一步说明；say之后是宾语从句they remain optimistic...prospects,even as引导让步状语从句。