Unit 2 You can make a difference（易错题专项练习·语法提升）英语外研版三起五年级下册（新教材）

Unit 2 You can make a difference 专题02 语法提升·易错题专项训练 高频易错点05 一般过去时动词不规则变化 高频易错点04 给出建议的句子 高频易错点03 表达感受的句子 高频易错点02 询问某人想法及观点（特殊疑问词） 高频易错点01 询问某人做了什么及其答语 高频易错点、易错点提示、小练笔、答题点拨 易错精讲 询问某人做了什么及其答语高频易错点01 询问某人过去做了什么，是一般过去时的核心交际句型，核心标志是用助动词 did 构成疑问句，答语需使用实义动词的 过去式（规则变化加 - ed，不规则变化需单独记忆）。 特殊疑问句 What + did + 主语（人称代词 / 名词）+ 动词原形 + 过去时间状语？ （did 是助动词，无单复数变化，后接动词原形） What did you do yesterday?（P12） 你昨天做了什么？ What did Lily do last weekend?（P12） 莉莉上周末做了什么？ 答语（肯定 / 否定形式） 肯定答语：主语 + 实义动词过去式 + 其他. I cleaned my room.（P12） 我打扫了我的房间。 She read a storybook.（P12） 她读了一本故事书。 否定答语：主语 + didn't + 动词原形 + 其他. I didn't play basketball.（P12） 我没有打篮球。 He didn't watch TV last night.（P12） 他昨晚没有看电视。 易错点提示 关键用法（三步走判断） 第一步：锁定疑问词——询问“做什么”的动作，固定用 what 开头； 第二步：添加助动词did——did用于一般过去时疑问句，无论主语是单数还是复数，did 形式不变，且其后的实义动词必须变回原形； 第三步：答语动词变形——肯定答语用实义动词过去式，否定答语用 didn't + 动词原形。小练笔 一、单项选择题 ( )1. —_______ did your father do last night? —He wrote a report. 第 1 页 共 14 页 学科网（北京）股份有限公司 A. What B. When C. Where D. How ( )2. —What _______ you _______ yesterday morning? —I visited my uncle. A. do; do B. did; do C. does; do D. will; do ( )3. Tom _______ his homework yesterday. He played outside all day. A. did B. does C. didn't do D. doesn't do ( )4. —What did Linda do last weekend? —She _______ to the zoo with her parents. A. go B. goes C. went D. going ( )5. —Did Mike play football yesterday? —No, he _______. He went swimming. A. did B. didn't C. was D. wasn't 二、语法填空题 1.—What _______ (do) your sister do last Sunday? —She _______ (wash) her clothes. 2.They _______ (not do) their homework last night. They watched a movie. 3.—_______ (do) you go to the park yesterday? —Yes, I _______ (walk) there with my dog. 4.My brother _______ (play) basketball with his friends last afternoon. 5.What _______ (be) your favorite activity last weekend? 点拨 一、单项选择 1. A 解析：答语是 “写报告”，表示具体动作，用 what 询问 “做什么”。 2. B 解析：时间状语是 yesterday morning，用一般过去时疑问句，结构为 did + 主语 + 动词原形。 3. C 解析：根据后半句 “整天在外面玩” 可知是否定含义，一般过去时否定结构是 didn't + 动词原形。 4. C 解析：问句是一般过去时，答语用实义动词过去式，go 的过去式是 went。 5. B 解析：一般过去时一般疑问句的否定回答结构是 No, 主语 + didn't。 二、语法填空 1. did; washed 解析：疑问句用助动词 did；答语用实义动词过去式，wash 的过去式是 washed。 2. didn't do 解析：一般过去时否定结构是 didn't + 动词原形。 3. Did; walked 解析：一般疑问句用助动词 did 开头；答语用实义动词过去式，walk 的过去式是 walked。 4. played 解析：时间状语是 last afternoon，用实义动词过去式 played。 5. was 解析：主语 activity 是单数名词，一般过去时主系表结构用 was。 询问某人想法及观点高频易错点02 询问某人想法及观点的特殊疑问句，核心是由 疑问词（why/who/which/how 等） 引导 一、询问观点 / 结论的原因（Why 引导，核心疑问词），用because回答 1.Why is Daming the real winner?（P16） Because he saw some cans and plastic bottles along the way and picked them up.（P16） 2.Why do you think she felt that way?（P19） Because she helped the new kid and felt happy from sharing.（P19） 二、询问核心观点对象（Who 引导） Who's the hero in your heart?（P20） 三、询问观点的践行方式（How 引导） How can you learn from Lei Feng?（P21） 易错点提示 语序规则：所有特殊疑问句均为 “疑问词 + 一般疑问句语序”（如 Why is Daming...?/How can you...?），无例外 小练笔 一、单项选择题 ( )1. —_______ was Lucy praised by the teacher? —Because she helped a new classmate find her way to the classroom. A. What B. Why C. When D. Where ( )2. —_______? —Because it shows helping others can bring friendship. A. What B. Why C. How D. Who ( )3. —_______ do you think is the most helpful person in your community? —The volunteer who often helps old people buy vegetables. A. Who B. What C. Which D. How ( )4. —_______ can we show our respect for Lei Feng? —We can clean the park for free on weekends. A. What B. Why C. How D. Where ( )5. —Why did Mike feel so happy after the picnic? —_______ he shared his food with a classmate who forgot to bring lunch. A. So B. Because C. For D. But 二、语法填空题 1.—Why _______ (be) Tom regarded as a kind boy? —Because he picked up rubbish in the school garden yesterday. 2.—Which activity _______ (do) you think is more meaningful, reading to the elderly or cleaning the street? —Reading to the elderly. 3.—Who _______ (be) the hero in your class? —Lily. She always helps classmates with their homework. 4.—How _______ (can) we pass on the spirit of helping others to our friends? —We can invite them to join volunteer activities together. 5.—Why do you think the girl _______ (feel) warm after giving her umbrella to a stranger on a rainy day? 点拨 一、单项选择题 1.B 解析：答语用 Because 说明原因，对应 “Why 询问行为被认可的原因” 2.B 解析：先选择喜欢的故事，再用 Why 追问原因 3.A 解析：答语是 “社区志愿者”（人物），用 Who 询问 “观点中的助人者” 4.C 解析：答语是具体行动（免费打扫公园），用 How 询问 “践行助人精神的方式” 5.B 解析：Why 引导的问句，答语用 Because开头 二、语法填空题 1.was 解析：事件发生在过去（昨天捡垃圾），主语 Tom 是单数，一般过去时中 be 动词用 was。 2.do 解析：主语 you 是第二人称，一般现在时中助动词用 do，询问对 “助人活动” 的偏好。 3.is 解析：询问客观观点（班级里的英雄），用一般现在时，who 视为单数，be 动词用 is。 4.can 解析：情态动词 can 表 “能够”，后接动词原形，询问 “传递助人精神的方式”。 5.felt 解析：事件发生在过去（雨天借伞），用一般过去时，feel 的过去式是 felt。 表达感受的句子高频易错点03 表达感受的句子核心是用 “be 动词 + 形容词” 或 “feel/felt + 形容词” 结构，描述情绪或身体感受 结构 1：主语 + be 动词（过去式 was/were）+ 形容词 I was tired but happy.（P17） 我很累但很开心。 They were busy but excited. 他们很忙但很兴奋。 结构 2：（时间状语从句）+ 主语 + feel/felt + 形容词 After I ate it, I felt full.（P19） 吃完后，我感到很满足。 When she helped the kid, she felt warm. 当她帮助那个小孩时，她感到很温暖。 易错点提示 be 动词过去式 was/were（单数主语用 was，复数主语用 were） feel 过去式 felt 小练笔 一、单项选择题 ( )1. —How did you feel after helping the old lady cross the street? — I _______ tired but warm. A. am B. was C. feel D. feels ( )2. After we finished the group work, all of us _______ very excited. A. were B. was C. felt D. feel ( )3. She _______ happy because she shared her toys with her new classmate. A. is B. was C. feel D. felt ( )4. After Tom finished the volunteer work, he _______ a little tired but proud. A. were B. was C. feel D. feels ( )5. —Why did Lily _______ full yesterday? —Because she shared her cake with a hungry kid. A. feel B. felt C. was D. is 二、语法填空题 1.After I helped my mom look after my little sister, I _______ (be) tired but happy. 2.They _______ (feel) excited when they finished the activity. 3.My brother _______ (be) not bored because he helped his classmate with math homework. 4.After we shared our snacks with the new kid, we all _______ (feel) warm in our hearts. 5.She _______ (be) happy but a little shy when the teacher praised her for helping others. 点拨 一、单项选择题 1. B 解析：问句询问过去的感受，需用一般过去时；主语 I 搭配 be 动词过去式 was，符合 “be 动词 + 形容词” 结构。 2. A 解析：主语 all of us 为复数，一般过去时中 be 动词用 were，excited 为情绪类形容词，适配感受表达。 3. B 解析：事件发生在过去，主语 she 为单数，用 be 动词过去式 was，描述过去的情绪感受。 4. B 解析：主语 Tom 为单数，一般过去时用 was，呼应 “be 动词 + 形容词” 核心句型，描述两种并列感受。 5. A 解析：前面有助动词 did，后接动词原形 feel，符合 “feel + 形容词” 结构，时态为一般过去时。 二、语法填空题 1. was 解析：事件发生在过去，主语 I 搭配 be 动词过去式 was，符合一般过去时要求。 2. felt 解析：描述过去的感受，feel 的过去式为 felt，适配 “feel + 形容词” 结构。 3. was 解析：主语 my brother 为单数，一般过去时 be 动词用 was，否定形式为 was not=wasn't。 4. felt 解析：事件发生在过去，feel 需用过去式 felt，贴合 “分享后产生感受” 的逻辑。 5. was 解析：主语 she 为单数，一般过去时 be 动词用 was，用 but 连接两种并列感受，符合句型结构。 给出建议的句子高频易错点04 核心是用 “should + 动词原形” 表达 “应该做某事”，核心时态为一般现在时。 We should learn from Lei Feng.（P21） 我们应该向雷锋学习。 语法：主语 + should + 动词原形，should 无单复数变化，后接动词原形。 We should not only help others on Lei Feng Day but also every day.（P21） 我们不仅应该在学雷锋日帮助别人，而且每天都应该这样做。 易错点提示 should 无单复数变化，后接动词原形；否定形式为 should not = shouldn't 小练笔 一、单项选择题 ( )1. —What _______ we do to care for the community? —We should clean the public areas regularly. A. should B. can C. did D. will ( )2. We _______ not only respect our parents but also help them with housework. A. must B. should C. need D. may ( )3. —_______ we waste food when there are many hungry people? —No, we shouldn't. We should save every grain. A. Should B. Do C. Did D. Will ( )4. They _______ learn to share their toys with classmates, because sharing brings friendship. A. is B. are C. should D. will ( )5. She _______ not only study hard but also take part in volunteer activities to help others. A. should B. must C. can D. may 二、语法填空题 1.We _______ (should) help the new kid get used to the class life, because he feels lonely. 2.People _______ (should not) throw rubbish everywhere. We should protect the environment. 3.He _______ (should) not only finish his homework on time but also help his sister with hers. 4._______ (should) we learn from those kind volunteers? Yes, their spirit is worth following. 5.My classmates and I _______ (should) organize more activities to help the elderly in the neighborhood. 点拨 一、单项选择题 1. A 解析：答语用 “should + 动词原形” 表建议，问句对应询问 “应该做什么”，故用 should。 2. B 解析：句子为递进式建议，符合 “should + not only...but also...” 结构，表 “应该做某事”。 3. A 解析：答语用 “shouldn't” 表否定建议，问句为一般疑问句，将 should 提前。 4. C 解析：此处需表达 “应该学会分享” 的建议，should 后接动词原形，符合句型要求。 5. A 解析：句子强调递进式建议，用 should 表达倡导性态度，贴合 “应该做某事” 的核心用法。 二、语法填空题 1. should 解析：表 “应该帮助”，should 后接动词原形 help，符合建议句型。 2. shouldn't 解析：表 “不应该扔垃圾”，should not 的缩写形式为 shouldn't。 3. should 解析：适配 “not only...but also...” 递进结构，should 后接并列动词原形短语。 4. Should 解析：一般疑问句中 should 提前，句首首字母大写，询问 “是否应该做某事”。 5. should 解析：主语为复数，should 无单复数变化，后接动词原形 organize，表建议。 一般过去时动词不规则变化高频易错点05 核心是用不规则动词的过去式描述过去发生的动作或存在的状态，无固定变化规则需特殊记忆，时态标志为过去时间背景（如故事场景、具体过去事件）。 核心原句 + 语法 1.The four friends went hiking.（P16） 四个朋友去徒步旅行了。 go→过去式 went 2.At first, Daming was in the front.（P16） 一开始，大明在前面。 be 动词不规则变化：am/is→was，are→were。 3.I saw some cans and plastic bottles along the way.（P17） 我在路上看到了一些罐头和塑料瓶。 see→过去式 saw 补充： say→said go→went do→did see→saw is/am→was are→were make→made have→had bring→brought give→gave eat→ate feel→felt hear→heard 否定形式：借助助动词 did+not，后接动词原形 如：I did not see the rubbish.（=I didn't see the rubbish.） 小练笔 一、单项选择题 ( )1. —What _______ you _______ in the park yesterday? —We saw some birds and took photos. A. do; see B. did; see C. does; see D. will; see ( )2. She _______ a new friend at the care home last Sunday. A. make B. makes C. made D. making ( )3. —Where _______ they go last weekend? —They went to the zoo to help feed small animals. A. do B. did C. are D. were ( )4. My mom _______ me a storybook yesterday evening. A. give B. gives C. gave D. giving ( )5. Tom _______ not at school yesterday because he helped his grandma. A. is B. was C. are D. were 二、语法填空题 1.He _______ (go) to the library with his sister yesterday afternoon. 2.We _______ (see) an old man carry heavy bags and helped him. 3.They _______ (make) a card for their teacher on Teachers' Day last year. 4.My dad _______ (bring) me a gift when he came back from Beijing. 5.—_______ (be) you at the volunteer activity last Saturday? —Yes, I _______ (be). I helped clean the community. 点拨 一、单项选择题 1. B 解析：yesterday 提示一般过去时，实义动词疑问句需用助动词 did，后接动词原形 see，符合 “did + 主语 + 动词原形” 结构。 2. C 解析：last Sunday 提示过去时，make 的不规则过去式为 made，描述过去发生的动作。 3. B 解析：last weekend 提示过去时，go 是实义动词，疑问句用助动词 did，无单复数变化。 4. C 解析：yesterday evening 提示过去时，give 的不规则过去式为 gave，符合时态要求。 5. B 解析：yesterday 提示过去时，主语 Tom 是单数，be 动词不规则过去式用 was，描述过去的状态。 二、语法填空题 1. went 解析：yesterday afternoon 提示过去时，go 的不规则过去式为 went，描述过去的动作。 2. saw 解析：句子描述过去发生的动作，see 的不规则过去式为 saw，与后半句 helped 时态一致。 3. made 解析：last year 提示过去时，make 的不规则过去式为 made，符合语法要求。 4. brought 解析：came 提示过去时，bring 的不规则过去式为 brought，前后时态保持一致。 5. Were; was 解析：last Saturday 提示过去时，主语 you 搭配 are 的不规则过去式 were；主语 I 搭配 am 的不规则过去式 was，符合 be 动词不规则变化规则。 综合训练 一、单项选择 ( )1. —_______ did you do at the community volunteer activity last Saturday? — I helped old people water the flowers. A. Where B. What C. When D. How ( )2. —What _______ your brother _______ yesterday afternoon? —He read a storybook to the kids in the hospital. A. did; do B. do; do C. does; do D. will; do ( )3. —_______ was Jim late for the volunteer meeting? —Because he helped a lost kid find his parents on the way. A. Why B. Who C. How D. What ( )4. —_______ do you think is the most helpful student in our class? —Li Mei. She always helps us with English homework. A. What B. Who C. Which D. Where ( )5. We _______ clean the park every weekend. It's our duty to keep the community tidy. A. should B. can C. will D. did ( )6. After finishing the charity sale, all of us _______ tired but happy. A. am B. is C. were D. are ( )7. —Did your sister _______ a gift to the homeless child last Sunday? —Yes, she gave a new schoolbag to him. A. give B. gave C. gives D. giving ( )8. My mother _______ not at home last night. She went to look after my sick grandma. A. is B. was C. are D. were ( )9. —_______ can we help the kids in the countryside? —We can send them some books and stationery. A. Why B. Who C. How D. What ( )10. —How did you _______ when you won the volunteer award? —I felt excited and proud. A. feel B. felt C. feels D. feeling 二、语法填空 1.—What _______ (do) your class do for the old people last month? —We _______ (sing) songs and _______ (dance) for them. 2.—_______ (be) your father at the environmental protection activity yesterday? —No, he _______ (be not). He _______ (have) to work overtime. 3.They _______ (not finish) their volunteer report last week. They need to hand it in today. 4.We _______ (should) care for the lonely elderly. Small kindness can make them warm. 5.After I helped my neighbor carry heavy boxes, I _______ (feel) a little tired but satisfied. 6.—_______ (do) you go to the animal shelter last weekend? —Yes, I _______ (feed) the homeless dogs and cats. 7.People _______ (should not) throw away the used books. We can give them to the kids in need. 8.—Why _______ (be) Lily so happy yesterday? —Because she _______ (make) a new friend at the volunteer club. 9.My brother _______ (see) a little boy crying on the street and _______ (help) him find his mom. 10.—_______ we _______ (organize) a book donation activity next week? —Good idea! We should try our best to help others. 三、句型转换（每空一词） 1.I did some volunteer work in the hospital last Sunday. （改为一般疑问句） _______ you _______ _______ volunteer work in the hospital last Sunday? 2.She shared her snacks with the hungry kid yesterday. （改为否定句） She _______ _______ her snacks with the hungry kid yesterday. 3.Tom was late for the meeting because he helped a stranger. （对划线部分提问） _______ _______ Tom late for the meeting? 4.We should help the disabled people cross the street. （改为一般疑问句） _______ we _______ the disabled people cross the street? 5.They felt warm after they gave their umbrellas to the strangers. （对划线部分提问） _______ _______ they _______ after they gave their umbrellas to the strangers? 四、补全短文（用括号内所给动词的适当形式填空） Last weekend, our class 1. _______ (have) a volunteer activity in the old people's home. I 2. _______ (get) up early in the morning. After breakfast, I 3. _______ (take) some fruits and a guitar to the bus stop. My classmates 4. _______ (wait) for me there. When we got to the old people's home, the grandparents 5. _______ (be) very happy. Some of us 6. _______ (clean) the rooms for them, some 7. _______ (talk) with them, and I 8. _______ (play) the guitar and 9. _______ (sing) old songs for them. Grandma Wang 10. _______ (tell) us some interesting stories about her youth. We 11. _______ (feel) very happy because we could do something for them. At noon, we 12. _______ (have) lunch with the grandparents. The food 13. _______ (be) simple but delicious. Before we left, we 14. _______ (promise) that we 15. _______ (come) to see them again next month. We all think we 16. _______ (should) spend more time with the elderly. They need love and care. 参考答案 一、单项选择题 1.B　　2.A　　3.A　　4.B　　5.A　　6.C　　7.A　　8.B　　9.C　　10.A 1.B 答语是具体动作，句中 “last Saturday” 提示用一般过去时，用 what 询问过去做的事情，符合 “What did + 主语 + 动词原形 + 过去时间状语” 结构。 2.A 句中 “yesterday afternoon” 表过去，一般过去时疑问句结构为 did + 主语 + 动词原形。 3.A 答语用 Because 说明原因，本句是 why 引导的特殊疑问句，用于询问动作发生的缘由。 4.B 答语是具体人物 Li Mei，本句用 who 询问观点中的助人者，符合特殊疑问句的语序规则。 5.A 本句表建议，用 should + 动词原形的结构，意为 “应该做某事”，用于提出倡导性主张。 6.C 句中 “after finishing the charity sale” 提示动作发生在过去，主语 all of us 是复数，be 动词过去式用 were，符合 “主语 + be 动词过去式 + 形容词” 的感受表达结构。 7.A 本句是一般过去时的一般疑问句，助动词 did 后接动词原形 give，符合语法规则要求。 8.B 句中 “last night” 表过去，主语 my mother 是单数，be 动词过去式用 was，用于描述过去的状态。 9.C 答语是帮助乡下孩子的具体方式，本句用 how 询问践行助人精神的方法，符合特殊疑问句的用法。 10.A 本句是一般过去时的疑问句，助动词 did 后接动词原形 feel，符合 “How did + 主语 + feel” 的感受询问句型。 二、语法填空 1.did; sang; danced　　2.Was; wasn't; had　　3.didn't finish　　4.should　　5.felt　　6.Did; fed　　7.shouldn't　　8.was; made　　9.saw; helped　　10.Should; organize 1.did; sang; danced 句中 “last month” 提示用一般过去时，疑问句用助动词 did；答语用实义动词过去式，sing 的过去式是 sang，dance 的过去式是 danced。 2.Was; wasn't; had 句中 “yesterday” 提示用一般过去时，主语 your father 是单数，be 动词用 was；否定形式为 wasn't；have to 的过去式为 had to。 3.didn't finish 句中 “last week” 提示用一般过去时，否定结构为 didn't + 动词原形，用于表达过去未完成的动作。 4.should 本句表建议，用 should + 动词原形 care，意为 “应该关心孤寡老人”，用于提出善意主张。 5.felt 句中 “after I helped my neighbor carry heavy boxes” 提示动作发生在过去，描述过去的感受用 feel 的过去式 felt，符合 “主语 + felt + 形容词” 结构。 6.Did; fed 句中 “last weekend” 提示用一般过去时，一般疑问句用助动词 did；feed 的过去式为 fed，用于表述过去的行为。 7.shouldn't 本句表否定建议，should not 的缩写为 shouldn't，后接动词原形 throw，用于提出禁止性主张。 8.was; made 句中 “yesterday” 提示用一般过去时，主语 Lily 是单数，be 动词用 was；make 的过去式为 made，用于描述过去发生的动作。 9.saw; helped 本句描述过去连续的动作，see 的过去式是 saw，help 的过去式是 helped，前后时态保持一致。 10.Should; organize 本句表建议发起活动，一般疑问句将 should 提前，后接动词原形 organize，用于征求他人意见。 三、句型转换 1.Did; do any　　2.didn't share　　3.Why was　　4.Should; help　　5.How did; feel 1.Did; do any 本句是一般过去时陈述句变一般疑问句，加助动词 did，实义动词 did 变回原形 do；some 在疑问句中变 any，符合语法转换规则。 2.didn't share 本句是一般过去时的否定结构，用 didn't + 动词原形 share，用于表达过去未发生的动作。 3.Why was 本句对原因状语提问用 why，主语 Tom 是单数，be 动词过去式用 was，符合特殊疑问句的转换要求。 4.Should; help 本句是 should 引导的陈述句变一般疑问句，将 should 提前，后接动词原形 help，符合句型转换规则。 5.How did; feel 本句对感受提问用 how，一般过去时疑问句结构为 How did + 主语 + feel，用于询问过去的情绪状态。 四、补全短文 1.had　　2.got　　3.took　　4.were waiting　　5.were　　6.cleaned　　7.talked　　8.played　　9.sang　　10.told　　11.felt　　12.had　　13.was　　14.promised　　15.would come　　16.should 1.had 句中 “last weekend” 提示用一般过去时，have 的过去式是 had，用于描述过去的活动。 2.got 本句描述过去的动作，get 的过去式是 got，用于表述过去发生的行为。 3.took 本句描述过去携带物品的动作，take 的过去式是 took，符合时态要求。 4.were waiting 本句强调过去某时正在进行的动作，用过去进行时 were waiting，用于表述过去的场景。 5.were 句中 “when we got to the old people's home” 提示用一般过去时，主语 the grandparents 是复数，be 动词过去式用 were。 6.cleaned 本句描述过去的动作，clean 的过去式是 cleaned，用于表述过去的行为。 7.talked 本句与 cleaned 并列，描述过去的动作，talk 的过去式是 talked，前后时态一致。 8.played 本句描述过去的动作，play 的过去式是 played，用于表述过去的行为。 9.sang 本句与 played 并列，描述过去的动作，sing 的过去式是 sang，前后时态一致。 10.told 本句描述过去讲故事的动作，tell 的过去式是 told，用于表述过去的行为。 11.felt 本句描述过去的感受，feel 的过去式是 felt，符合 “主语 + felt + 形容词” 结构。 12.had 本句描述过去吃午饭的动作，have 的过去式是 had，have lunch 的过去式为 had lunch。 13.was 句中 “at noon” 提示用一般过去时，主语 the food 是单数，be 动词过去式用 was，用于描述过去的事物状态。 14.promised 本句描述过去的承诺，promise 的过去式是 promised，用于表述过去的行为。 15.would come 本句是宾语从句，主句是过去时，将来时变过去将来时 would come，符合从句时态规则。 16.should 本句表建议，should 无时态变化，后接动词原形 spend，用于提出倡导性主张。 $