高中英语中的主语从句是复合句的一种，它在句子中作为主语存在，通常用来表达一个完整的思想或情况。主语从句可以由多种类型的引导词引领，这些引导词在句子中扮演着不同的角色，有时是连词，有时是代词，有时是连接副词。以下是针对提供的部分内容进行的详细解释和练习题解析：
一．翻译部分：
1. 谁将去接他（Who will pick him up）is not decided.
2. 哪个班会赢得这场足球赛（Which class will win the football match）is not clear.
3. 他能否买到飞机票（Whether he can buy an airplane ticket）doesn’t matter much.
4. 我们如何去那里（How we will get there）is a question.
5. 你刚才告诉我的（What you just told me）was really a surprise.
6. 他什么时候出国（When he will go abroad）is being discussed.
7. 他为什么哭（Why he was crying）is not clear.
8. It is clear（that）他是一个乞丐（That he is a beggar）.
9. (你要请谁)Who you will invite is not important.
10. (我们将在哪里举行篮球赛)Where we will hold the basketball game is not clear.
二．找出主语从句及其引导词，并指出引导词的作用：
1. That we shall be late is certain. 引导词：That，不充当成分。
2. That the driver could not control his car was obvious. 引导词：That，不充当成分。
3. It is certain that we shall be late. 引导词：that，不充当成分。
4. It was obvious that the driver could not control his car. 引导词：that，不充当成分。
5. Is it possible that they will come tomorrow? 引导词：that，不充当成分。
6. It is clear that he was telling the truth. 引导词：that，不充当成分。
7. It’s probable that we’ll be a little late. 引导词：that，不充当成分。
8. What caused the accident is a complete mystery. 引导词：What，充当主语。
9. It worried her a bit that her hair was turning grey. 引导词：that，不充当成分。
10. It shocked me that Peter didn’t tell anybody where he was. 引导词：that，不充当成分。
11. Who was responsible for the accident is not yet clear. 引导词：Who，充当主语。
12. It’s a pity that you can’t go with us. 引导词：that，不充当成分。
13. What he did is not yet known. 引导词：What，充当主语。
14. It is said that he has been there many times. 引导词：that，不充当成分。
15. It is not yet clear who was responsible for the accident. 引导词：who，充当主语。
16. When they will have the sports meet is still a question. 引导词：When，充当主语。
17. It seems that he has lost something. 引导词：that，不充当成分。
18. What he said at the meeting encouraged everyone. 引导词：What，充当主语。
19. What caused the accident was a broken bottle. 引导词：What，充当主语。
20. It remains a problem whether it is true. 引导词：whether，不充当成分。
21. Whoever breaks the law is sure to be punished. 引导词：Whoever，充当主语。
22. What she looks like doesn’t matter. 引导词：What，充当主语。
23. How this happened is not clear to anyone. 引导词：How，充当主语。
24. Whoever comes is welcome. 引导词：Whoever，充当主语。
25. Whether he’ll come here isn’t clear. 引导词：Whether，不充当成分。
三．用适当的引导词填空：
1. It is likely that we will have rain tomorrow.
2. It matters little whether you come or not.
3. It seems as if we might be late.
4. Who will be elected the president is still unknown.
5. It is obvious that she is unhappy.
6. What you said yesterday made everyone laugh.
7. It's important who will take charge of the project.
8. It is suggested that we should start early.
9. It's uncertain whether the plan will work.
10. It's surprising that he didn't recognize me.
通过这些练习题，我们可以看到主语从句在句子中起着核心作用，它们可以由that、who、which、what、when、where、why、how、whether等引导，有时候这些词在从句中并不充当语法成分，仅仅起到引导作用，而有时候则在从句中担任主语、宾语或表语的角色。理解和掌握主语从句的构造和用法对于提高英语阅读、写作和口语能力至关重要。
