13.3 主语从句
主语从句是在句子中充当主语的从句。它与其它名词性从句一样，通常由连接代词或连接副词引导。
13.3.1 由that 引导的主语从句
That she lacks experience is obvious. 她缺少经验，这是显然的。
That you will win the medal seems unlikely. 你想获得奖牌看起来是不可能的。
That you are so indifferent bothers me. 你如此冷淡使我很烦恼。
13.3.2 由连接代词引导的主语从句
* What you need is more practice. 你需要的是更多的练习。
* Which of them escaped from the prison is still a mystery.
他们哪一个是从监狱里逃跑的，仍然是个谜。
13.3.3 由连接副词引导的主语从句
When they will come hasn’t been made public. 他们什么时候来还没有公布。
Where she has gone is not known yet. 她去了哪儿，还不知道。
How the prisoner escaped is a mystery. 犯人是如何逃跑的是个迷。
Why he did it will remain a puzzle forever. 为什么他做那件事将永远是个谜团。
13.3.4 由whether引导的主语从句
Whether he will join us won’t make too much difference. 他是否加入我们，没有太大的差别。
Whether she is coming or not doesn’t matter too much. 她来不来都无关紧要。
13.3.5. 由 what 引导的主语从句
What she did is not yet known. 她干了什么尚不清楚。
What I want to know is this. 我想知道的就是这事。
What you need is more practice. 你所需要的是更多的训练。
13.3.6 以it作形式主语的主语从句
1） it + be + 形容词 + 从句
It is doubtful whether she will be able to come. 她是否能来令人怀疑。
It is essential that he should be here by the weekend. 周末之前，他应该到这里是必要的。
It was clear (that) his words pleased her. 显然他的话使她很高兴。
2） it + be + 名词 + 从句
* It is common knowledge that the whale is not a fish. 鲸鱼不是鱼，这是常识。
* It is no surprise that Bob should have won the game. 鲍勃会赢得这场比赛，这不足为奇。
3） it + 动词 (+宾语或状语) + 从句
It does not interest me whether you go or not. 我对你去不去不感兴趣。
It shocked me that Peter did not tell anybody where he was.
让我吃惊的是彼得没有告诉任何人他在哪里。
It happened that she was out. 碰巧她外出了。
4） it + 动词的被动语态 + 从句
It is thought that he is the best player. 大家都认为他是最好的选手。
It is estimated that the vase is 2000 years old. 据估计这个花瓶有2000年的历史。
13.3.7 由whatever, whoever, whichever 等引导的主语从句
Whatever was said has left us much to think. 这里说的话都应当保密。
Whoever says that is a liar. 说那话的人是个骗子.
Whichever comes in first will receive a prize. 谁先到就会获奖。
8. 由 just because 引导的主语从句
由just because 引导的主语从句通常只用于 “Just because…doesn’t mean…”句型中。
Just because her eyes don’t tear, doesn’t mean her heart doesn’t cry.
只是因为眼泪没有掉下来，并不代表她在心里没有哭泣。
Just because he’s over sixty doesn’t mean he must retire.
仅仅是年过60这一点并不意味着他一定退休。60这一点并不意味着他一定退休。
