When I try to understand ____ that prevents so many Americans from being as happy as one might ...

When I try to understand ____ that prevents so many Americans from being as happy as one might ...

C

试题分析：句意：当我试图去理解是什么阻挡了许多美国人得到他们应有的快乐时，我发现个两个原因。这是强调句型，其结构是：It was+被强调部分+that/who（人）+其他。判断强调句型的方法是把It was that这三个词去掉，整个句子不缺成分，意思完整。这里被强调的是疑问词what，因为是宾语从句，所以强调句型应该用陈述语序，what在从句中做主语，why不能做主语，故选C。 点评：本题难度适中。强调句型是高中阶段的重难点之一，也是高考的热点，需要考生有分析理解句子的结构的能力。近几年高考把强调句型与其他从句混合在一起考查更增加了试题的难度。 即学即练：It was after hegot what he had desired ____he realized it was not soimportant. A.that      B.when       C.since        D. as 解析：A。句意：该句强调时间状语从句after he got what he haddesired，题干意思是“得到他所梦寐以求的东西后他才意识到一切都不那么重要”。不要误选B。