四、用所给单词的正确形式补全短文。
Subway is fast and comfortable. But do you feel 16. (happy) when people play music or videos on the subway? It's not a problem now. There are some new 17. (rule) for the subway in our city.
The first new rule is “no using loudspeakers (扬声器)”. Subway riders must follow it when they 18. (take) the subway. They 19. (have) to use their earphones when they listen to music or watch movies on 20. (they) phones. If some people don't 21. (follow) the new rule, the subway workers can stop them and take them to the police(警察).
There 22. (be) also some other rules. People cannot bring 23. (bike) into the subway station. People cannot eat or 24. (drink) in subway cars.
Many people 25. (understand) and welcome the rules. And they think the rules can help subway riders. They also need the same rules on buses and trains.

16. unhappy 17. rules 18. take 19. have 20. their 21. follow 22. are 23. bikes 24. drink 25. understand

【分析】
本题为英语短文填空题型，要求用所给单词的正确形式补全内容，解题时需先通读短文理解大意，再结合上下文语境、语法规则（如词性、时态、单复数、代词形式等）对所给单词进行变形，逐个确定每个空的正确形式。
【解析】
16. 前文提到地铁快且舒适，转折后询问是否“不开心”，故将happy变为否定形容词unhappy；
17. some后需接可数名词复数，rule的复数形式为rules；
18. when引导的时间状语从句，主从句均用一般现在时，主语为they，故用动词原形take；
19. 主语为they，一般现在时，故用动词原形have；
20. 此处修饰名词phones，需用形容词性物主代词，they的形容词性物主代词为their；
21. don't为助动词否定形式，后接动词原形，故用follow；
22. there be句型中主语为复数名词rules，故be动词用are；
23. 此处泛指“自行车”这类事物，需用可数名词复数bikes；
24. cannot为情态动词，后接动词原形，且与eat并列，故用drink；
25. 主语many people为复数，一般现在时，故用动词原形understand。
【答案】
16. unhappy 17. rules 18. take 19. have 20. their 21. follow 22. are 23. bikes 24. drink 25. understand
【知识点】
名词单复数、一般现在时、词形变化
【点评】
本题考查英语基础词汇变形与语法运用，结合语境和基础语法规则即可完成，是英语学习中的常见基础题型，有助于巩固词汇和语法知识。
【难度系数】
0.6