强调句

It's the answer that led those who have been told for so long by so many to be cynical, and fearful, and doubtful of what we can achieve to put their hands on the arc of history and bend it once more toward the hope of a better day.——奥巴马演讲

1 句子主干

It's the answer that led those to put their hands on the arc of history and bend it once more toward the hope of a better day.

为强调句，去掉 It's…that...后句子结构完整语义通顺。
the answer led those (people) to put their hands on the arc of history and bend it once more toward the hope of a better day. 

2 “cynical”一词是很狡猾的词。很多专业英语学生都很不容易掌握此词。在英语中，有很多这样的词，有个根本含义，即根义。从英语中读意思已经达到。但翻译到汉语，也就是说，译文则要根据上下文来决定用什么样的词来表述。但无论如何，也没有“淡漠的”意思。这一点，请这位译者好好注意一下。它的根本含义是“认为人人都是自私的，所以不相信任何人”。

3 sb be told to do sth 告诉某人去做某事； for so longer 长久以来  by so many 被很多人

4 “对于那些长期以来被灌输不信，恐惧和怀疑我们到底能做出什么的人们来说，今晚（的一切）也是一个回答。我们可以掌控历史前行的弧线，并把这一弧线弯曲，令它重新朝着更好的未来延伸。”