四、按要求完成句子。
16. Many trees and flowers are planted in our school.（改为一般疑问句）
many trees and flowers in your school?
17. My father allows me to play computer games at weekends.（改为被动语态）
I computer games at weekends.
18. One of the classrooms is often cleaned.（改为否定句）
One of the classrooms often .
19. Did you give back the book to the library last Friday?（改为被动语态）
the book the library last Friday?
20. My mum made me do the dishes this morning.（改为被动语态）
I the dishes by my mum this morning.

16. Are; planted 17. am; allowed; to; play; by; my; father 18. isn't; cleaned 19. Was; given; back; to; by; you 20. was; made; to; do

【分析】
本题考查英语句型转换，核心涉及被动语态的各类句式转换（一般疑问句、否定句、主动变被动）。解题思路：16题将一般现在时被动语态陈述句改一般疑问句，需提前be动词；17题主动变被动，需对应时态和主语调整be动词，同时注意allow sb to do的被动结构；18题被动语态改否定句，在be动词后加not；19题一般过去时主动变被动，需提前be动词，保留give back to短语；20题make sb do的被动结构要还原不定式符号to，结合时态调整be动词。
【解析】
16. 原句为一般现在时被动语态（be+过去分词），改一般疑问句时将be动词Are提前，故填Are；planted。
17. 主动语态变被动语态，一般现在时主语I对应be动词am，allow sb to do的被动结构为sb be allowed to do，动作执行者用by引出，故填am; allowed; to; play; by; my; father。
18. 被动语态改否定句，在be动词is后加not缩写为isn't，过去分词cleaned不变，故填isn't; cleaned。
19. 一般过去时主动变被动，原句为一般疑问句，主语the book对应be动词Was，保留give back to短语，动作执行者用by you，故填Was; given; back; to; by; you。
20. make sb do的被动结构需还原不定式符号to，一般过去时主语I对应be动词was，结构为was made to do，故填was; made; to; do。
【答案】
16. Are; planted 17. am; allowed; to; play; by; my; father 18. isn't; cleaned 19. Was; given; back; to; by; you 20. was; made; to; do
【知识点】
被动语态、句型转换、主动变被动
【点评】
本题围绕初中英语核心考点被动语态的各类转换展开，涵盖一般疑问句、否定句、主动转被动的规则，需掌握特殊结构（如make、allow的被动用法），是基础题型，难度适中。
【难度系数】
0.6

五、语法填空。
Do you know the seismograph（地动仪）? It 21. (say) that there were many earthquakes thousands of years ago in China. Without doubt, a lot of people 22. (die) in earthquakes. At that time, a man named Zhang Heng decided to invent 23. instrument to help people. He tried many 24. (time). At last, the seismograph 25. (invent) by him. It was used for 26. (know) about the direction of earthquakes. There were eight dragons 27. a ball in the mouth of each on the seismograph. How did it work? For example, 28. an earthquake happened in the east, the ball in the eastern dragon would fall. And then people would know the earthquake happened. One day, one ball in the Western dragon 29. (sudden) fell. Soon people learned that an earthquake had happened in the 30. (west) area on that very day. I think it is a great invention in the world. Do you think so?

21. is said 22. died 23. an 24. times 25. was invented 26. knowing 27. with 28. if 29. suddenly 30. Western

【分析】
本题为语法填空题，需结合语境、固定搭配、语法规则逐一分析每个空：1. 第21空考查固定句型It is said that...；2. 第22空描述过去地震的情况，需用一般过去时；3. 第23空考查不定冠词的用法；4. 第24空考查可数名词复数；5. 第25空考查一般过去时的被动语态；6. 第26空考查be used for doing的固定搭配；7. 第27空考查介词with表伴随的用法；8. 第28空考查条件状语从句的引导词；9. 第29空考查副词修饰动词；10. 第30空考查形容词修饰名词。
【解析】
1. 第21空：固定句型It is said that...意为“据说……”，故填is said；
2. 第22空：描述过去地震中人们死亡的情况，用一般过去时，die的过去式为died，故填died；
3. 第23空：instrument是可数名词单数，且以元音音素开头，表泛指用不定冠词an，故填an；
4. 第24空：many后接可数名词复数，time此处意为“次数”，复数为times，故填times；
5. 第25空：地动仪与invent是被动关系，且动作发生在过去，用一般过去时的被动语态was invented，故填was invented；
6. 第26空：be used for后接动名词，表“被用来做某事”，故填knowing；
7. 第27空：with表“带有”，符合“龙嘴里有球”的语境，故填with；
8. 第28空：if引导条件状语从句，表“如果”，符合语境，故填if；
9. 第29空：修饰动词fell需用副词，sudden的副词形式为suddenly，故填suddenly；
10. 第30空：修饰名词area需用形容词，west的形容词形式为Western，故填Western。
【答案】
21. is said 22. died 23. an 24. times 25. was invented 26. knowing 27. with 28. if 29. suddenly 30. Western
【知识点】
一般过去时、被动语态、冠词用法
【点评】
本题为初中英语常见语法填空题，考察基础语法点，涵盖固定句型、时态语态、冠词、介词、词性转换等，难度适中，侧重考查学生基础语法的掌握与运用能力。
【难度系数】
0.6