文档文本内容
it 做形式主语单项选择题练习题（教师版）
一、单项选择题（50 道）
1. It is ______ for us to finish our homework on time.
A. important B. importantly C. importance D. unimportantly
答案：A 解析：it is + 形容词 + for sb. to do sth. 结构，此处需用形容词，important（重要的）符合句意；
B、D是副词，C是名词，均不符合语法。
2. It is kind ______ you to help the old man cross the street.
A. for B. of C. to D. with
答案：B 解析：形容词kind（善良的）描述人的品质，需用介词of，构成it is + 形容词 + of sb. to do sth.
结构；for用于修饰“事情”的形容词后。
3. It is difficult ______ him to solve this math problem.
A. of B. to C. for D. with
答案：C 解析：形容词difficult（困难的）描述“解决数学题”这件事，需用介词for，构成it is + 形容词
+ for sb. to do sth. 结构，固定搭配。
4. It is ______ to learn a foreign language well in a short time.
A. possible B. possibly C. impossible D. impossibly
答案：C 解析：it is + 形容词 + to do sth. 结构，需用形容词；结合句意，短时间内学好外语是“不可能
的”，impossible（不可能的）符合，A不符合常识，B、D是副词。
5. ______ is necessary for everyone to keep healthy.
A. This B. That C. It D. He
答案：C 解析：此处需用it作形式主语，替代后面的不定式短语to keep healthy，固定句式it is + 形容词
+ for sb. to do sth.，其他选项不能作形式主语。
6. It is a good idea ______ a walk after dinner.
A. take B. to take C. taking D. takes
答案：B 解析：it is + 名词短语 + to do sth. 结构，真正主语是不定式to take a walk，固定搭配，其他选项
不符合语法。
7. It is said ______ he will come to our school next week.
A. that B. which C. what D. who
答案：A 解析：it is said that... 是固定句式，it作形式主语，that引导真正主语从句，无实际含义，不可省
略，其他选项不能引导此类从句。
8. It ______ that she missed the bus this morning.
A. happen B. happens C. happened D. happening
11
答案：C 解析：it happens that... 表示“碰巧……”，this morning提示用一般过去时，happen的过去式是
happened，A是原形，B是第三人称单数，D是现在分词，均不符合时态。
9. It doesn’t matter ______ you are late or not.
A. that B. if C. whether D. what
答案：C 解析：it doesn’t matter whether...or not 是固定搭配，whether表“是否”，可与or not连用；if不
能与or not连用，that、what不符合句意。
10. It is clear ______ he is good at English.
A. that B. where C. when D. how
答案：A 解析：it is + 形容词 + that从句结构，it作形式主语，that引导真正主语从句，从句语义完整，
用that连接，其他选项引导的从句语义不完整。
11. It is no use ______ about the bad weather.
A. complain B. complaining C. to complain D. complained
答案：B 解析：it is no use doing sth. 是固定搭配，it作形式主语，真正主语是动名词complaining，意为
“做某事没用”，其他选项不符合固定结构。
12. It is ______ of you to give up your seat to the kid.
A. polite B. politely C. impolite D. impolitely
答案：A 解析：it is + 形容词 + of sb. to do sth. 结构，需用形容词；结合句意，给小孩让座是“有礼貌
的”，polite（礼貌的）符合，C（不礼貌的）语义相反，B、D是副词。
13. It is essential ______ us to learn basic computer skills.
A. of B. for C. with D. to
答案：B解析：形容词essential（必不可少的）描述“学习电脑技能”这件事，需用介词for，构成it is +
形容词 + for sb. to do sth. 结构，固定搭配。
14. ______ is impossible for a student to know everything.
A. This B. That C. It D. There
答案：C 解析：固定句式it is + 形容词 + for sb. to do sth.，it作形式主语，替代后面的不定式短语，其他
选项不能作形式主语，There be句型表“存在”，不符合句意。
15. It is surprising ______ he passed the difficult exam.
A. that B. if C. whether D. how
答案：A 解析：it is + 形容词（surprising） + that从句结构，it作形式主语，that引导真正主语从句，从
句语义完整，无需其他疑问词，故选A。
16. It is wise ______ her to ask the teacher for help.
A. for B. of C. to D. with
答案：B 解析：形容词wise（明智的）描述人的品质，需用介词of，构成it is + 形容词 + of sb. to do sth.
结构，区别于修饰“事情”的for sb.。
17. It is dangerous ______ alone at night.
A. go out B. going out C. to go out D. went out
22
答案：C 解析：it is + 形容词 + to do sth. 结构，真正主语是不定式to go out，it作形式主语，其他选项不
符合语法（A是原形，B是动名词，D是过去式）。
18. It is reported ______ the city will hold a sports meeting next year.
A. that B. what C. which D. who
答案：A 解析：it is reported that... 是固定句式，it作形式主语，that引导真正主语从句，表“据报
道……”，其他选项不能引导此类从句。
19. It ______ to me that I left my keys at home.
A. occur B. occurs C. occurred D. occurring
答案：C 解析：it occurs to sb. that... 表示“某人突然想到……”，结合句意，“想到忘带钥匙”是过去发
生的事，用一般过去时，occur的过去式是occurred。
20. It is necessary that we ______ hard every day.
A. study B. studies C. studied D. studying
答案：A 解析：it is necessary that... 结构中，that从句需用虚拟语气（should + 动词原形），should可省略，
故用study（动词原形）。
21. It is no good ______ too much time playing games.
A. spend B. spending C. to spend D. spent
答案：B 解析：it is no good doing sth. 是固定搭配，it作形式主语，真正主语是动名词spending，意为
“做某事没好处”，其他选项不符合固定结构。
22. It is kind ______ him to help me with my homework.
A. for B. of C. at D. in
答案：B 解析：形容词kind（善良的）描述人的品质，需用介词of，构成it is + 形容词 + of sb. to do sth.
结构，固定搭配，其他介词不符合。
23. It is difficult ______ finish the work in two days.
A. for we to B. for us to C. of us to D. of we to
答案：B 解析：it is + 形容词 + for sb. to do sth. 结构，for后接宾格us（we的宾格），difficult修饰“完成
工作”这件事，用for，A中we是主格，C、D介词错误。
24. It is obvious ______ he didn’t tell the truth.
A. that B. which C. what D. when
答案：A 解析：it is + 形容词（obvious，明显的） + that从句结构，it作形式主语，that引导真正主语从
句，从句语义完整，无需其他疑问词。
25. ______ is useful to learn a second language.
A. This B. That C. It D. He
答案：C 解析：固定句式it is + 形容词 + to do sth.，it作形式主语，替代后面的不定式短语to learn a
second language，其他选项不能作形式主语。
26. It is strange ______ she didn’t come to school today.
A. that B. if C. whether D. where
33
答案：A 解析：it is + 形容词（strange，奇怪的） + that从句结构，it作形式主语，that引导真正主语从句，
从句语义完整，if、whether表“是否”，where表“哪里”，均不符合句意。
27. It is advisable that we ______ early tomorrow morning.
A. leave B. leaves C. left D. leaving
答案：A 解析：it is advisable that... 结构中，advisable（明智的）表建议，that从句需用虚拟语气（should
+ 动词原形），should可省略，故用leave。
28. It is harmful ______ us to smoke.
A. for B. of C. to D. with
答案：A 解析：形容词harmful（有害的）描述“吸烟”这件事，需用介词for，构成it is + 形容词 + for
sb. to do sth. 结构，固定搭配，其他介词不符合。
29. It is said that ______ will rain tomorrow.
A. this B. that C. it D. he
答案：C 解析：此处it是真实主语，指代天气，固定表达“it will rain”（将要下雨）；前面的it是形式主
语，替代that从句，注意区分形式主语和真实主语。
30. It happened that I ______ my old friend in the park.
A. meet B. meets C. met D. meeting
答案：C 解析：it happened that... 中，happened是过去式，从句需用对应过去时，meet的过去式是met，
A是原形，B是第三人称单数，D是现在分词，均不符合时态。
31. It is important ______ we should protect the environment.
A. that B. if C. whether D. what
答案：A 解析：it is important that... 结构，it作形式主语，that引导真正主语从句，从句中should可省略，
其他选项不能引导此类从句，不符合句意。
32. It is useless ______ to persuade him to change his mind.
A. try B. trying C. to try D. tried
答案：B 解析：it is useless doing sth. 是固定搭配，it作形式主语，真正主语是动名词trying，意为“做某
事无用”，区别于it is + 形容词 + to do sth. 结构。
33. It is polite ______ you to say “thank you” when you get help.
A. for B. of C. to D. at
答案：B 解析：形容词polite（有礼貌的）描述人的品质，需用介词of，构成it is + 形容词 + of sb. to do
sth. 结构，固定搭配。
34. It is easy ______ him to play the piano.
A. of B. for C. with D. in
答案：B 解析：形容词easy（容易的）描述“弹钢琴”这件事，需用介词for，构成it is + 形容词 + for sb.
to do sth. 结构，固定搭配。
35. It is clear ______ she is the best student in our class.
A. that B. who C. what D. where
44
答案：A 解析：it is + 形容词（clear，明显的） + that从句结构，it作形式主语，that引导真正主语从句，
从句语义完整，无需其他疑问词。
36. ______ is a pity that you missed the concert.
A. This B. That C. It D. There
答案：C 解析：it is a pity that... 是固定句式，it作形式主语，替代后面的that从句，表“……真是遗憾”，
其他选项不能作形式主语。
37. It is reported ______ many students will take part in the competition.
A. that B. which C. what D. who
答案：A 解析：it is reported that... 是固定句式，it作形式主语，that引导真正主语从句，表“据报
道……”，其他选项不能引导此类从句。
38. It doesn’t matter ______ you take the bus or walk.
A. that B. if C. whether D. how
答案：C 解析：it doesn’t matter whether...or not 是固定搭配，whether表“是否”，可与or（or not）连用；
if不能与or连用，that、how不符合句意。
39. It is good ______ every morning.
A. exercise B. exercising C. to exercise D. exercised
答案：C 解析：it is + 形容词 + to do sth. 结构，真正主语是不定式to exercise，it作形式主语，表“每天
早上锻炼是好的”；A是名词，B是动名词，D是过去式，均不符合语法。
40. It is foolish ______ him to make such a mistake.
A. for B. of C. to D. with
答案：B 解析：形容词foolish（愚蠢的）描述人的品质，需用介词of，构成it is + 形容词 + of sb. to do
sth. 结构，固定搭配。
41. It is impossible ______ us to finish the work ahead of time.
A. of B. for C. with D. to
答案：B 解析：形容词impossible（不可能的）描述“提前完成工作”这件事，需用介词for，构成it is +
形容词 + for sb. to do sth. 结构，固定搭配。
42. It is believed ______ the earth goes around the sun.
A. that B. what C. which D. who
答案：A 解析：it is believed that... 是固定句式，it作形式主语，that引导真正主语从句，表“人们相
信……”，从句是客观事实，用一般现在时。
43. It is essential that we ______ careful in class.
A. be B. is C. are D. was
答案：A 解析：it is essential that... 结构中，essential（至关重要的）表必要，that从句需用虚拟语气
（should + 动词原形），should可省略，be是动词原形，符合要求。
44. It is no use ______ about the past.
A. worry B. worrying C. to worry D. worried
55
答案：B 解析：it is no use doing sth. 是固定搭配，it作形式主语，真正主语是动名词worrying，意为“担
心过去是没用的”，其他选项不符合固定结构。
45. It is kind ______ you to invite me to your birthday party.
A. for B. of C. at D. in
答案：B 解析：形容词kind（善良的）描述人的品质，需用介词of，构成it is + 形容词 + of sb. to do sth.
结构，固定搭配，其他介词不符合。
46. It is difficult ______ solve this problem without help.
A. for me to B. of me to C. for I to D. of I to
答案：A 解析：it is + 形容词 + for sb. to do sth. 结构，for后接宾格me（I的宾格），difficult修饰“解决
问题”这件事，用for，B介词错误，C、D中I是主格，不符合语法。
47. It is surprising ______ he can speak three languages.
A. that B. if C. whether D. how
答案：A 解析：it is + 形容词（surprising，令人惊讶的） + that从句结构，it作形式主语，that引导真正
主语从句，从句语义完整，无需其他疑问词。
48. ______ is necessary to drink enough water every day.
A. This B. That C. It D. There
答案：C 解析：固定句式it is + 形容词 + to do sth.，it作形式主语，替代后面的不定式短语to drink
enough water，其他选项不能作形式主语。
49. It is said that he ______ to America next month.
A. go B. goes C. will go D. went
答案：C 解析：it is said that... 结构中，that从句时态需结合语境，next month（下个月）提示用一般将来
时，will go符合，A是原形，B是一般现在时，D是过去时。
50. It happened that we ______ the same school.
A. attend B. attends C. attended D. attending
答案：C 解析：it happened that... 中，happened是过去式，从句需用对应过去时，attend的过去式是
attended，A是原形，B是第三人称单数，D是现在分词，均不符合时态。
6
