备战2021 中考英语 导练案 考点23 状语从句 （学生版）

备战2021 中考英语 导练案 考点23 状语从句 （学生版）

考点 23 状语从句 一、时间状语从句 1. 引导时间状语从句的连词 从属连词 用法 例句 While ＂与…… 同时 ，在…… 期 间＂，从句常用延续性动词 或表示状态的词 Don’t talk loud while（as）others are working. 别人工作时，请勿大声说话。 When ＂当……时＂，表示主句的 动作和从句的动作同时或先 后发生，从句的动词可用延 续性动词，也可用非延续性 动词 It was raining when we arrived. 我们到达时，天正下着雨。 when you read the poem a second time, the meaning will become clearer to you. 当你再读一遍这首诗，你就会更清楚它的含义。 As ＂正当，一边……一边，随 着＂，表示两个动作同时发 生或某事发生时，另一个动 作发生了 As time went on, his theory proved to be correct. 随着时间的推移，他的理论被证明是正确的。 Till/Until 用于 肯定句 时， 表示＂ 直 到……为止＂，主句必须为 延续性动词；notuntil/till 表 示＂直到……才＂，主句常 用短暂性动词 We shall wait until/till he comes back. 我们将一直等到他回来。 I didn’t leave until/till she finished her homework. 直到她完成作业我才离开。 Since ＂自……以来＂，主句用一 般现在时或现在完成时，从 句用一般过去时 I have heard lot of good things about you since I come back from abroad. 自从我从国外回来，我已经听许多好 的事情。 Before 在……以前 He must finish all the work before he goes home. 回家之前他必须完成所有的工作。 After 在……之后 Let’s play football after school. 放学后我们打篮球吧。 【知识拓展】 时间状语从句的时态问题：在时间状语从句和条件状语从句中，主句如果使用一般将来时态，从 句使用一般现在时表示将来，即所谓的＂主将从现＂。 As soon as I arrive in Beijing, I will ring you up. 我一到北京就给你打电话。 You’ll fall behind the others unless you study hard. 如果你不努力学习，你将会落后于其他人。 2. when，while，as 引导时间状语从句的区别 when，while，as 显然都可以引导时间状语从句，但用法区别非常大。 ① when 可以和延续性动词连用，也可以和短暂性动词连用；而 while 和 as 只能和延续性动词连用。 Why do you want a new job when you’ve got such a good one already? 你已经找到如此好的工作，为何还想再找新的？ （get 为短暂性动词） Sorry, I was out when you called me. 对不起，你打电话时我刚好外出了。 （call 为短暂性动词） Strike while the iron is hot. 趁热打铁。 （is 为延续性动词，表示一种持续的状态） The students took notes as they listened. 学生们边听课边做笔记。 （listen 为延续性动词） ② when 从句的谓语动词可以在主句谓语动作之前、之后或同时发生；while 和 as 从句的谓语动作必须 是和主句谓语动作同时发生。 a. 从句动作在主句动作前发生，只用 when。 When he had finished his homework, he took a short rest. （finished 先发生） 当他完成作业后，他休息了一会儿。 When I got to the airport, the guests had left. （got to 后发生） 当我赶到飞机场时，客人们已经离开了。 b. 从句动作和主句动作同时发生，且从句动作为延续性动词时，when，while，as 都可使用。 ①When / While / As we were dancing, a stranger came in. （dance 为延续性动词） 当我们跳舞时，一位陌生人走了进来。 ②When / While / As she was making a phonecall, I was writing a letter. （make 为延续性动词） 当她在打电话时，我正在写信。 c. 当主句、从句动作同时进行，从句动作的时间概念淡化，而主要表示主句动作发生的背景或条件时， 只能用 as。这时，as 常表示＂随着……＂ ＂一边……，一边……＂之意。 As the time went on, the weather got worse. 随着时间的过去，天气变得更糟糕了。 The atmosphere gets thinner and thinner as the height increases. 随着高度的增加，大气越来越稀薄。 As years go by, China is getting stronger and richer. 随着时间一年一年过去，中国变得越来越富强了。 The little girls sang as they went. 小姑娘们一边走，一边唱。 The sad mother sat on the roadside, shouting as she was crying. 伤心的妈妈坐在路边，边哭边叫。 d. 在将来时的从句中，常用 when，且从句要用一般时代替将来时。 You shall borrow the book when I have finished reading it. 在我读完这本书后，你可以借阅。 When the manager comes here for a visit next week, I’ll talk with him about this. 下周，经理来这参观时，我会和他谈谈此事。 ③ when 用于表示＂一……就……＂的句型中（指过去的事情）。 sb. had hardly（＝scarcely）done sth. when. . . ＝Hardly / Scarcely had sb. done sth. when I had hardly / scarcely closed my eyes when someone knocked at the door. ＝Hardly / Scarcely had I closed my eyes when someone knocked at the door. 我刚一闭上眼，就有人在敲门了。 I had hardly / scarcely entered my room when the telephone rang. ＝Hardly / Scarcely had I entered my room when the telephone rang. 我刚一走进房门，电话就响了。 3. 比较 until 和 till 此两个连词意义相同。肯定形式表示的意思是＂做某事直至某时＂，动词必须是延续性的。否定形式 表达的意思是＂直至某时才做某事＂。动词为延续性或非延续性都可以。正确使用这两个连词的关键之一 就在于判断句中的动词该用肯定式还是否定式。 肯定句：I slept until midnight. 我一直睡到半夜时醒了。 Wait till I call you. 等着我叫你。 （在肯定句中可用 before 代替。例如：Let’s get in the wheat before the sun sets.） 否定句：She didn’t arrive until 6 o’clock. 她直到 6 点才到。 Don’t get off the bus until it has stopped. 公共汽车停稳后再下车。 I didn’t manage to do it until you had explained how. 直到你教我后，我才会做。 区别： （1）until 可用于句首，而 till 通常不用于句首。 Until you told me, I had heard nothing of what happened. 直到你告诉我以前，出了什么事我一点也不知道。 （2）until when 疑问句中，until 要放在句首。 —Until when are you staying? —Until next Monday. 注意：否定句可用另外两种句式表示。 （3）Not until 在句首，主句用倒装。 Not until the early years of the 19th century did man know what heat is. 直到 19 世纪初，人类才知道热为何物。 Not until I began to work did I realize how much time I had wasted. 直到工作，才认识到我已蹉跎了许多岁月。 （4）It is not until that It was not until I began to work that I realized how much time I had wasted. （5）表示＂一……就……＂的结构 hardly/scarcely when/before, no sooner than 和 as soon as 都可以表示＂一……就……＂的意思。 I had hardly / scarcely got home when it began to rain. 刚回家，就下起雨来了。 I had no sooner got home than it began to rain. As soon as I got home, it began to rain. 注意：如果 hardly, scarcely 或 no sooner 置于句首，句子必须用倒装结构。 Hardly / Scarcely had I got home when it began to rain. No sooner had I got home than it began to rain. 二、目的状语从句 英语里可以用 to，in order to，so as to，so that，in order that 来表示目的。 1. to，in order to，so as to 引导目的状语短语，构成简单句。 He has to earn lots of money in order to/to/so as to raise his family. 他赚很多钱是为了养家糊口。 2. so that，in order that 引导目的状语从句，构成复合句，并且从句中谓语动词常与 can，could，may， might 等情态动词连用。 Speak clearly so that/in order to everybody can understand you. 请说清楚一点，这样每个人都能听得懂。 目的状语从句 结果状语从句 3. so that so that 既可以引导目的状语从句又可以引导结果状语从句。引导目的状语从句时译为＂为了＂，引导结 果状语从句时可译为＂以便＂。 He workedn hard at his lessons so that he could gain high grades in the exams. 他努力学习功课，争取考试能获得好的成绩。 He workedn hard at his lessons, so that he gained high grades in the exams. 他努力学习，结果考试取得了好成绩。 so that 引导目的状语从句时，表示＂以便，为了＂，从句中常使用 can，could，may，might，will，would， should 等情态动词或助动词；引导结果状语从句时，从句中一般不用 can 和 may 等词。 He has to earn so lots of muney so that he can buy his children nice food and clothes. 他必须赚很多钱才能给他的孩子提供好的饮食和衣服。 4. suchthat 在 suchthat 句型中，such 修饰名词，意思是＂如此……以至于……＂，suchthat 引导四种不同的句子结 构。 （1）such+a(n)+形容词+单数名词+that 从句 This is such a good book that all of us like it very much. 这是一本很好的书，我们大家都喜欢读它。 （2）such+形容词+复数名词+that 从句 They are such good students that the teacher likes them. 他们都是很好的学生，老师喜欢他们。 so that suchthat sothat 结果状语从句 （3）such+（形容词）+不可数名词+that 从句 It was such fime weather yesterday that we went swimming. 昨天天气很好，我们去游泳了。 （4）one（no，any，all，many，some，several 等）+such+可数名词+that 从句 There are many such good books that I can’t decide which one to choose. 有这么多的好书，我无法决定选择哪一本。 5. sothat sothat 句型中的 so 是副词，常用来修饰形容词或副词，意思是＂如此/这么……以至于……＂。 （1）常用句型：主语+谓语+so+adj./adv.+that 从句 The boy ran so fast that I couldn’t catch him. 这个男孩跑得太快了以至于我追不上他。 （2）so+形容词+ a(n)+单数名词+that 从句 She made so good a meal that we all ate far too much. 她做的饭菜那么好吃，结果我们都吃得太多了。 （3）so+many/much few/little（少）+名词+that 从句 当名词前有 many、much、few、little（少）等词修饰时，句子中要用 sothat 而不能用 suchthat。 There was so little water in the jar that it was not enough for all of us. 缸里的水太少了，不够我们这些人用。 注意：当 little 的意思是＂小＂时，仍用 suchthat。 6. 用 in order that 引导：in order that 的意思是＂为了＂。 He is working hard in order to pass the examination. =He is working hard in order that he can pass the examination. 7. 用 in case 引导：in case 此时的意思是＂以防＂＂以备＂。 I always keep a bottle of wine by in case friends call round. 我平时总存着一瓶酒以备朋友来时喝。 注意：in case 引导目的状语从句与引导条件状语从句时的意思不一样。 8. 在目的状语从句中也有这样一个引导词——in order that，容易与它混淆的词组是 in order to，后者并 不能引导状语从句。下面看一下两者有哪些具体差别。 首先要注意的是，in order that 与 in order to 译文相同，都译作＂为了……＂，不同之处在于：in order that+ 从句；in order to+动词原形。 in order that+从句构成目的状语从句，表明主句行为目的；in order to+动词原形构成目的状语，不成 从句。 I get up early in order that I can catch the early bus. I get up early in order to catch the early bus. 为了能赶上早班车，我很早就起床了。 He works hard in order that he can obtain a higher position. He works hard in order to obtain a higher position. 为了升职，他很努力地工作。 另外，目的状语从句还有一个特点： 由于目的都是未来的行为，所以从句中一般用表示未来可能性时态，当然还可以用 will，would， can 等。 He studies English very hard in order that he will go abroad one day. 为了将来有一天能够出国，他很努力地学习英语。 in order that 与 in order to 只是结构相似，含义相同，但两者用法却有较大差异，不能够互换使用，因为 后者不能引导目的状语从句，只能跟动词原形构成目的状语。 三、条件状语从句 条件状语从句，即在某种条件下，一件事情可能发生。在英语中由连接词 if 或 unless 等引导的状语从 句叫作条件状语从句。条件是指某一件事情实现之后（状语从句中），一件事情（主句）才能发生，通常译 作＂假如，只要，如果＂等意思。条件状语从句中，主从句的时态要遵循＂主将从现＂的原则。即，主句 是将来时态时，从句用一般现在时代替将来时态。 引导条件状语从句的连词或词组有：if(如果)，unless(除非)，as long as(只要)等。如果主句是将来时， 条件状语从句也用一般现在时来表示。如： I will stay at home if it rains tomorrow. 如果明天下雨，我就待在家。 You can’t learn English well unless you work hard. 除非你努力学习，否则是学不好英语的。 1.if 引导的条件状语从句 表示在某种条件下某事很可能发生。 If we pay much attention to the earth, we’ll have a better world. 如果我们多关爱地球，就会拥有一个更美好的世界 If it rains tomorrow, what shall we do? 如果明天下雨，我们怎么办？ If you ask him, he will help you. 如果你请他帮忙，他会帮你的。 If you fail in the exam, you will let him down. 如果你考试不及格，你会让他失望的。 注意：if 还可以引导虚拟条件句，表示不可实现的条件，从句中多用一般过去时或过去完成时。 What would happen if there were no water? 如果没有水会怎样？ 2. unless 引导的条件状语从句 unless 的意思是＂如果不，除非＂。可与 if not 互换。 You will fail in English unless you work hard. 你英语考试会不及格的，除非你更加努力。 You will fail to arrive there in time unless you start earlier. 如果你不早点动身，你就不能及时赶到那儿。 Unless it rains, the game will be played. 除非下雨，比赛将照常进行。 3. as /so long as 引导的条件状语从句 as /so long as 的意思是＂只要＂ So long as you’re happy, I will be happy. 只要你高兴，我就高兴。 You may borrow my book as long as you keep it clean. 只要你保持书的清洁，你就可以把我的书借去。 4. once 引导的条件状语从句 once 引导的条件状语从句，意为＂一旦……就＂，从句可置于主句前或后。 Once you begin, never stop. 一旦开始，就绝不要停止。 Maths is easy to learn once you understand the rules. 一旦你理解了规则，数学就不难学了。 提示：在条件状语从句中，用一般现在时代替一般将来时，用一般过去时代替过去将来时。 If the weather is bad next week, we’ll put off the climbing. 如果下周天气不好，我们将推迟爬山。 Father told me if I worked hard he would buy me a gift. 爸爸告诉我，如果我努力学习，他会给我买一份礼物。 5. 引导条件状语从句最常用的连词是 if，常见的 if 条件状语从句表示在某条件下，某事很可能发生， 条件是可能存在的，主句中某种情况发生的概率也是很高的。如： If you ask him, he will help you. 如果你请他帮忙，他会帮你的。 If you fail in the exam, you will let him down. 如果你考试不及格，你会让他失望的。 If you have finished the homework, you can go home. 如果你作业做完了就可以回家了。 另外，if 从句还表示不可实现的条件或根本不可能存在的条件，也就是一种虚拟的条件或假设。从句多 用一般过去时或过去完成时，表示对现在或过去的一种假设。如： If I were you, I would invite him to the party. 如果我是你，我会邀请他参加聚会。 I would have arrived much earlier if I had not been caught in the traffic. 要不是交通堵塞，我本会来得早一些。 6. if 条件句的时态搭配 （1）if 从句用一般现在时，主句用一般将来时。 If he runs he’ll get there in time. 如果他用跑的，他就会及时赶到那儿。 The cat will scratch you if you pull her tail. 如果你拉猫的尾巴，它就会抓你。 （2）if 从句用一般现在时，主句用 may/might/can。 If the fog gets thicker the plane may/might be diverted. 如果雾再大一些，飞机可能就会改在别的机场降落。 If it stops snowing we can go out. 如果雪停了，我们就可以出去。 （3）if 从句用一般现在时，主句用 must/should。 If you want to lose weight you must/should eat less bread. 如果你想减肥，你必须少吃面包。 （4）if 从句用一般现在时，主句用一般现在时。 If you heat ice it turns to water. (也可用 will turn)如果把冰加热，它就会化成水。 （5）if 从句用现在进行时，主句用一般将来时。 If you are looking for Peter you’ll find him upstairs. 如果你是在找彼得，上楼就会找到他。 （6）if 从句用现在完成时，主句用一般将来时。 If you have finished dinner I’ll ask the waiter for the bill. 如果你吃完了，我就叫服务生来算账。 【知识拓展】 1. 在以 when，before，as soon as 等引导的时间状语从句，也适用＂主将从现＂原则，即如果主句是一 般将来时，从句则用一般现在时。 I’ll tell her the good news when she comes back. 当她回来的时候，我将把这个好消息告诉她。 she will give you a call as soon as she returns. 她一回来就会给你电话。 2.If 条件句的同义句：祈使句，and /or+将来时态的陈述句。 Work hard, and you will make great progress. = If you work hard, you will make great progress. 如果你努力学习，你就会取得大的进步。 Hurry up, or you will be late. =If you don’t hurry up, you will be late. 如果你不快点，你就要迟到了。 【巧学妙记】 ＂ if ＂ 引导的条件状语从句的记忆口诀 if 条件句不一般，几个要点记心间； 条件句,放在前，逗号要放句中间。 条件句表真实，主将从现要遵从； 条件句非真实，虚拟语气用到位。 1. Spud Webb remained in another basketball league for a year ________the NBA took notice of him. A. when B. before C. since D. after 2. The story is interesting everybody likes it very much. A. very; that B. so; that C. such; that D. such; because 3. Nobody knows if he ____，If he ____here, I’ll call you at once. A. will come; will arrive B. will comes; arrives C. comes; will arrive. D. comes, arrives. 4. Your spoken English will certainl y improve ______ you practise it every day. A. though B. before C. if D. until 5. She read the text loudly all the students could hear her. A. because B. since C. when D. so that 6. I advise you to go to an English corner________ you can improve your listening and speaking. A. so that B. even though C. whether D. as soon as 7. I are not going out________ you have finished your homework. A. that B. but C. so D. until 8. —I am really proud of my group________ we’re always discussing and sharing study secrets together. —How important the group work is! A. until B. as if C. because D. though 9. Remember to keep in touch with your teachers and classmates ________ graduation. A. when B. before C. during D. after 10. — How soon shall we leave the airport?—We won't leave ________ we make sure that everything is OK. A. because B. until C. as soon as D. if 11. —________ you know little about this art form, you can read a book to learn more. — OK, I will. A．SinceB．But C．Before D．However 1. 【2020 •黔西南州】The Chinese doctors went to Italy to help the patients________they knew it was dangerous. A. because B. if C. though D. as soon as 2. 【2020 •黑龙江哈尔滨市 】—Tim, our foreign teacher Ms. Green will go back to England next week. —Really? Let's have a party to say goodbye to her ________ she is free this weekend. A. unless B. if C. though 3. 【2020 •江苏省苏州市】Check what you have written _______ you hand in your application form. A. since B. before C. after D. while 4. 【2020 •山东滨州市 】—I think I am the shyest in my class. What should I do? —Be more active in class, ________ you can improve your ability to express yourself. A. so that B. unless C. or D. although 5.【2020 •温州市】Little Mary says good night to her parents________ she goes to bed every day. A. if B. until C. before D. unless 6.【2020 •南通市】Max got lost and was trapped in the forest for 10 hours _______ a farmer nearby found him. A. if B. since C. until D. after 7. 【2020 •天津市】You’d better tidy up your room ________ your father comes back. A．so B．or C．before D．but 8. 【2020 •江苏省淮安市】Our school basketball team will win the next match _________ they practise more. A. if B. before C. though D. while 9.【2020 •江苏泰州市】Father is too tired today. Don’t call him ________ it is necessary. A. if B. unless C. when D. whether 10.【2020 •无锡市】I think the coffee beans are from Brazil, ________ I’m not completely sure. A. because B. since C. though D. whether 11.【2020 •徐州市】We’re not very close friends________ we’ve known each other for a long time. A. until B. although C. as D. if 12.【2020 •扬州市】Lucy held her head up like a queen________ Bill was telling his tale. A. after B. before C. while D. until 13.【2020 •镇江市】My parents gave red packets to my cousin every Spring Festival___________ she got a job, because she said she was able to make money. A. after B. when C. until D. since 14.【2020 •江西省】It was great in the end ________ we had a terrible time at the beginning. A. if B. unless C. when D. although 15.【2020 •沈阳市】_______ Simon has done well in his studies, he still works really hard. A. Since B. If C. Although D. Unless 16.【2020 •铁岭葫芦岛】________ she is very young, she can take good care of herself. A. If B. Unless C. Since D. Although 17.【2020 •青海省】I was still feeling hungry ________ I had eaten some sandwiches. A. so B. though C. since 18.【2020 •青岛市】In Chinese families, people won't start dinner ________ the elders take their seats. A. after B. when C. because D. until 19.【2020 •山东日照】________ the traffic was heavy, we still got to the railway station on time. A. As B. Unless C. When D. Although 20.【2020 •山西省】Swimming is, of course, interesting. But ________ we plan to go swimming, being safe must come first. A. though B. when C. unless 21.【2020 •云南省】—Excuse me. Where is the nearest hotel? —Just go down this road ________ you see a library. It’s across from it. A. until B. because C. however D. though 22.【2020 •安徽省】Our English teacher is nice and patient she is very strict with us. A．if B．as C．unless D．though 23.【2020 •福建省】In some cities of China, you'll get fined ________ you don't walk along the crosswalk while crossing the road. A．if B．though C．until 24.【2020 •上海市】Vivian will take her daughter to the amusement park________she gets the tickets． A．if B．until C．although D．unless 25.【2020 •甘肃武威市】You will feel cold ________ you don't wear a coat. A. so B. though C. if D. unless 26.【2020 •海南省】President Xi encourages all Chinese people to plant trees_________ our country can be greener and more beautiful. A. so that B. as long as C. even though 27.【2020 •黑龙江牡丹江、鸡西地区】Wechat Pay (微信支付) makes our life convenient. We can buy things ________ we don't take any money. A. because B. so that C. even though 28.【2020•长沙市】________ you have problems, just let me know. I'll always be there for you. A. However B. Whatever C. Whenever 29.【2020•长沙市】________ the outbreak of COVID-19 is a terrible blow to the country, the government is trying hard to bring the situation under control. A. Although B. If C. Unless 30.【2020•岳阳市】The movie Nezha is__________ educational ________ I want to see it again. A. so; that B. such; that C. too; to 31.【2020•益阳市】You can surf the Internet _________ you want to know more about the 2020 World Middle School Games. A. if B. although C. until 32.【2020•郴州市】We should protect the environment ________ we can make a better world to live in. A. so that B. even though C. as soon as 33.【2020•湖南省邵阳市】—Don't forget to protect your eyes well__________ you take online classes. —OK. Thank you, Sir. A．if B．though C．as if 34.【2020•襄阳市】— It’s said that Zhou Jielun will hold a concert next month in Xiangyang. — I’m sure the fans will be happy _______ it’s true. A. until B. although C. before D. if 35.【2020•孝感市】We will make fewer mistakes __________ we are careful enough. A. as long as B. so that C. as far as D. even if 36.【2020•湖北省宜昌市】—What do you feel ____________ you are looking through the old pictures? —How time flies! A. because B. though C. while D. unless 37.【2020•江苏省淮安市】—When shall we go on a picnic, Saturday or Sunday? —_________ is OK. I'm free the whole weekend. A. Neither B. All C. Either D. Both 38.【2020•辽宁丹东】I don’t like Sun Cinema ________ it has bad service. A. because B. although C. unless D. until 39.【2020•辽宁丹东】—I'm afraid we can't work out the math problem________the teacher helps us. —That's true. It's too difficult. A. if B. unless C. because D. as soon as 40.【2020•东营市】________ he is dead, Kobe Bryant’s spirit will continue to influence us. A. If B. Until C. Because D. Although 41.【2020•广西北部湾】_______ you are in trouble, you can ask the policeman for help. A. Whenever B. Whatever C. However 42.【2020•内蒙古包头市】She says that she'll have to close the restaurant ______ business improves. A．if B．after C．unless D．when 1.【2020•安徽省中考二模】You can't go to the reading room ________ you have a school ID card. It is only for students. A. if B. although C. unless D. since 2. 【2020•安徽省芜湖市三模】—Tom, do you know if Sam _______ to my party next week? —I think he will come if he __________. A. comes; will invite B. will come; will be invited C. comes; invites D. will come; is invited 3.【2020•黑龙江省牡丹江市市中区一模】In China, we can’t start eating ________everyone is at the table. It’s one of our Chinese table manners. A. since B. until C. although 4.【2020•江苏省南京市建邺区中考二模】___________I have to live my life without books, the days would all be empty. A. Though B. Unless C. If D. Until 5. 【2020•江西省宜春市安高市中考二模】Helen was very rude to me. I refuse to speak to her again __________ she says sorry. A. until B. if C. because D. since 6. 【2020•山东省菏泽市曹县二模】Mary is afraid of the dog. She will run away ________she sees it. A. although B. as soon as C. so that 7. 【2020•合肥市庐阳区中考二模】 The theater will close down _________more money can be raised to support it. A. so B. unless C. since D. when 8. 【2020•安徽省合肥市瑶海区中考二模】 —Emma, what do you want to be in the future? —I want to be a doctor. This has been my dream_______ I was a kid. A. since B. when C. until D. before 9. 【2020•甘肃省张掖市中考一模】 —How long have you lived in the new building? —_____2010. A. After B. In C. Since D. Before 10. 【2020•湖南省长沙市长郡双语实验中考一模】Those plants in the yard will not die________ you take good care of them. A. until B. unless C. if