以下文段摘自2017年高考全国卷英语试题阅读第3篇：

Some of the world’s most famous musicians recently gathered in Paris and New Orleans to celebrate the first annual International Jazz Day. UNESCO( United Nations Educational, Scientific and Cultural Organization) recently set April 30 as a day to raise awareness of jazz music, its significance, and its potential as a unifying(联合) voice across cultures.

Despite the celebrations, though, in the U.S. the jazz audience continues to shrink and grow older, and the music has failed to connect with younger generations.

It’s Jason Moran’s job to help change that. As the Kennedy Center’s artistic adviser for jazz, Moran hopes to widen the audience for jazz, make the music more accessible, and preserve its history and culture.

“Jazz seems like it’s not really a part of the American appetite,” Moran tells National Public Radio’s reporter Neal Conan. “What I’m hoping to accomplish is that my generation and younger start to reconsider and understand that jazz is not black and white anymore. It’s actually color, and it’s actually digital.”

这篇文章以欢庆第一届“国际爵士乐日”（ International Jazz Day）引出下文，指出这个节日的创立能够帮助人们加深对爵士乐的认识，认识它的重要意义，并提出它能促进不同文化间的交流融合（to raise awareness of jazz music, its significance, and its potential as a unifying voice across cultures）。

但是，接下来文章以一个“though”字转折了一下，指出尽管有这个庆祝节日，美国欣赏爵士乐的人还是越来越少，而且大多是老人，年轻一代并不喜欢爵士乐（the music has failed to connect with younger generations）。

因此，Jason Moran希望能改变这个状况。

他表示，“What I’m hoping to accomplish is that my generation and younger start to reconsider and understand that jazz is not black and white anymore. It’s actually color, and it’s actually digital.” 这句话实际上包含一个主语从句。我们将通过这个例子来总结一下主语从句的用法。

What I’m hoping to accomplish is that my generation and younger start to reconsider and understand that jazz is not black and white anymore

这句话的主语是一个小从句，“what i am hoping to accomplish ”，即我希望能实现什么。后面的“that my generation and younger start to … anymore” 是what的具体内容，what作宾语，即to accomplish what。

因此，整句话的意思就是说我希望我这一代人，包括年轻人在内，都能重新思考，明白爵士不再是黑人或白人的专利。

主语从句，顾名思义，就是说在句子中担当主语的是一个从句。

第一，像what引导的主语从句，在句子中what是要做成分的。

比如说What you said yesterday is right. 你昨天说的是对的。what作宾语，即said what yesterday。

第二，从句的位置？

1、它通常放在主句的谓语动词之前，比如说这篇文章里的这句话，主句的谓语动词是is，从句what i am hoping to accomplish放在is的前面。

2、或者用形式主语it代替。真正的主语则放在句子末尾。如果不是从句不是特别长，也可以直接放在句首。

举两个例子。

A. It is still a question whether she will come or not. 她来不来还是个问题。

这句话实际的主语是whether she will come or not，将句子还原一下，就变成了whether she will come or not is still a question。

B. It is still unknown which team will win the match. 哪一支队伍将赢得比赛还是个未知数，

同理，这句话的真正主语是which team will win the match，实际上是which team will win the match is still unknown。

第三，还有以下几种特殊情况，我们不能使用1的句式，不能把主语从句放在句首，位于谓语动词之前，这些情况下真正的主语都放在句子后面。下面这些也是常见固定句型。

A. It is said (reported) that   据说，据报道，……。

比如，it is said that the president will visit our school next week.

据说总统下周要来访我校。

这句话真正的主语是the president will visit our school next week，但是在这个句式中，我们不能写成the president will visit our school next week is said/reported。

B. It happens (occurs)

1）It occurred to somebody；

比如，It occurred to him that he failed in the exam. 他想到他考试挂了。

（he failed in the exam occurred to him） ×

occur to somebody是一个固定表达，意思是（观念、想法或主意）出现在头脑中，什么什么被想起。

It didn’t occur to her to ask for help. 就是说，她没有想到请别人帮忙。

（To ask for help did not occur to her） ×

2）It happens that，意思是发生、出现、碰巧……。

It happens that I am not there that day.  碰巧那天我不在那儿。

It would happen that the software was written in a week instead of three months.

偏偏这套软件就在一周内被编写出来，而不是三个月。

Tip: 有一点需要注意，像The idea occurred to him in a dream（这个主意是他在梦中想到的）这样的句子就不是主语从句了，这句话的主语就是the idea。

C. It doesn’t matter how/whether/if  意思是怎样，是否……都没关系，不重要。

It doesn’t matter whether he comes or not. 他来不来都没关系。

（whether he comes or not doesn’t matter）×

It doesn't matter how you do it. 你怎么做都没关系。

（how you do it doesn’t matter） ×

D. 疑问句中。

Is it likely that it will rain in the evening? 傍晚有可能下雨吗？It作形式主语，真正的主语是that it will rain in the evening。

How does it happen that you know her?  你怎么会碰巧认识她的？真正的主语是that you know her。

最后总结一下今天所说的，

一、介绍了主语从句中从句的位置。一般有两种形式。

二、介绍了四中特殊情况下主语从句不能放在句首，当然，这部分也可以当作固定表达来记忆。