初中状语从句加练习

壮语从句 状语从句是由从句担任的状语，在句子中可修饰谓语（或其它动词）、形容词、副词或是整个句子，它可以用来 表 关于同志近三年现实表现材料材料类招标技术评分表图表与交易pdf视力表打印pdf用图表说话 pdf 示时间、地点、原因、目的、结果、条件、方式、比较、让步等。状语从句是一较大的语法项目，也是近几年高考 题 快递公司问题件快递公司问题件货款处理关于圆的周长面积重点题型关于解方程组的题及答案关于南海问题 中常见的一个重要试点。高考中已考查了时间、让步、地点、条件、目的等状语从句，这些从句仍是今后高考热点，应作充分准备。同时对方式状语从句也应引起重视。不同的状语从句所使用的连接词也各不相同。见下表： 状语从句名称 时间状语从句 when, as, while, whenever, after, before, till (until), since, once, as soon as (或the moment ), by the time, no sooner … than, hardly (scarcely) … when, every time等 地点状语从句 where 和wherever 条件状语从句 if, unless, so (as) long as, on condition that, so (as) far as, if only ( = if ) 原因状语从句 because, since, as, now that（既然） 结果状语从句 so that （从句谓语一般没有情态动词）, so … that, such … that 目的状语从句 so, so that（从句谓语常有情态动词）, in order that, in case（以防，以免） 让步状语从句 although, though, as, even if (though), however, whatever, whether … or, no matter who (when, what, …) 等 比较状语从句 than, so (as) … as, the more … the more 方式状语从句 as, as if (though), the way, rather than等 一、时间状语从句w。 1、当while, when, as引导时间状语从句时的区别： (1) while引导的状语从句中动词必须是持续性。谓语动词多为进行时，或状态动词的一般时。while 的这些用法可用when代替。 E.g. Please keep quiet while (when) others are studying； (2) when除可指一段时间外，还可用来指一点时间，等于 “at the time”，也就是说when引出的时间状语从句中的谓语动词可以是终止性的，也可以延续性的。因此主句和从句的谓语可以是一般时，进行时，或完成时。 E.g. When I went into the lab, the teacher was doing an experiment.（when不能换成while）He often makes mistakes when he is speaking English.（when可换成while (3) as常可与when，while通用，但强调“一边、一边”。 as 用于引出一个持续性动词表示“在……期间”时，其谓语通常只能是那些含有动作(action)和发展(development) 意味的动词，一般不能是那些不用于进行时态的动词(如 be, seem, love, want, agree, see, know, have 等) E.g. As (when, while) I was walking down the street, I noticed a police car in front of number 37. (4) when有时代替if，引导条件句，意为“如果”、“假如” E.g. I’ll come when (if) I’m free. (1) 若主句表示的是一个短暂性动作，从句表示的是一个持续性动作，三者都可用： He fell asleep when [while, as] he was reading. 他看书时睡着了。 2、till, until引导时间状语短语或状语从句，用于否定句时，结构为not …until (till)，主句谓语动词延续与非延续皆可，意为“直到…才…”。用于肯定句时，只与延续性动词连用，表示“到…为止”。E.g. They played volleyball until (till) it got dark./ They didn’t talk（延续性动词）until (till) the interpreter（译员）came./ He didn’t go to bed（非延续性动词）until (till) his father came back.；until可以放在句首，till则不行，E.g. Until the last minute of the match we kept on playing./ Not until he finished his work did he go home.（倒装）；till, until只用于时间，以下句子是错误的：We walked till the edge of the forest.（要用as far as或to）。 2Whenever 无论什么时候，随时 1）. Whenever we’re in trouble, they will help us. 2）. I go to the theatre, whenever I am free. 3since: 主句用完成时，从句用一般过去时 We have known each other since we were children. We have been friends (ever since) since we met at school. It is …… (一段时间)+since+一般过去时态句子。 It is two years since my sister married. 4. once 一旦…就 Once you begin, you must go on. 你一开了头，就应该继续下去。 5 一---就--- （hardly…when/, no sooner…than　和as soon as都可以表示"一…就…"的意思。）例如： 　 I had hardly 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 或no sooner置于句首，句子必须用倒装结构。例如： 　 Hardly had I got home when it began to rain. 　 No sooner had I got home than it began to rain. 二、地点状语从句 引导地点状语从句的连词是where 和wherever等。 E.g. Sit wherever you like. Make a mark where you have a question. 三、条件状语从句 条件状语从句分真实性（有可能实现的事情）与非真实性（条件与事实相反或者在说话者看来不大可能实现的事情）条件句。引导条件状语从句的词（组）主要有if, unless, so (as) long as, on condition that, so (as) far as, if only ( = if )。注意：条件从句中的if 不能用whether替换。 E.g. If he is not in the office, he must be out for lunch. You may borrow the book so long as you keep it clean. So far as I know（据我所知）, he will be away for three months. You can go swimming on condition that ( = if ) you don’t go too far away from the river bank. If he had come a few minutes earlier, he could have seen her. 四、原因状语从句 because, since, as引导原因状语时注意使用上的区别： 1.如果原因构成句子的最主要部分,一般用because ,因此because引导的从句往往放在句末。用why提问的句子，一定用because回答。 E.g. He had to stay at home yesterday because he was ill.；2.如原因已为人们所知，或不如句子的其他部分重要，就用as，或 since。since比as更正式些。as和since引导的从句一般放在句子的开头。 E.g. As you are tired, you had better rest./ Since everyone is here, now let’s begin. 五、结果状语从句 结果状语从句是表示事态结果的从句，通常主句是原因，从句是结果。由so that （从句谓语一般没有情态动词）, so … that, such … that等引导。 E.g. She was ill, so that she didn’t attend the meeting. He was so excited that he could not say a word. She is such a good teacher that everyone admires her. 六、目的状语从句 引导目的状语从句最常用的词（组）是so, so that（从句谓语常有情态动词）, in order that, in case（以防，以免）等。 E.g. Speak clearly, so that they may understand you. She has bought the book in order that she could follow the TV lessons. He left early in case he should miss the train. 七、让步状语从句 让步状语从句可由although, though, as, even if (though), however, whatever, whether … or, no matter who (when, what, …) 等引导。注意：as引导的让步状语从句一般是倒装的。 E.g. Though he is a child, he knows a lot. Child as he is, he knows a lot. Whatever ( = No matter what ) you say, I’ll never change my mind. 八、比较状语从句 比较状语从句常用than, so (as) … as, the more … the more等引导。 E.g. I have made a lot more mistakes than you have. He smokes cigarettes as expensive as he can afford. The busier he is, the happier he feels. 九、方式状语从句 方式状语从句常由as, as if (though), the way, rather than等引导。 E.g. You must do the exercise as I show you. He acted as if nothing had happened. 十、使用状语从句时要注意的几个问题 1、在时间和条件（有时也在方式、让步等）从句中，主句是一般将来时，从句通常用一般现在时表示将来。 E.g. We’ll go outing if it doesn’t rain tomorrow. I’ll write to you as soon as I get to Shanghai. 2、有些时间、地点、条件、方式或让步从句，如果从句的主语与主句主语一致（或虽不一致，是it），从句的谓语又包含动词be ，就可省略从句中的“主语 + be”部分。 E.g. When (he was) still a boy of ten, he had to work day and night. If (you are) asked you may come in. If (it is) necessary I’ll explain to you again. 3、注意区分不同从句：引导的是什么从句，不仅要根据连词，还要根据句子结构和句意来判别。以where为例，能引导多种从句。 E.g. You are to find it where you left it.（地点状语从句） Tell me the address where he lives.（定语从句，句中有先行词） I don’t know where he came from.（宾语从句） Where he has gone is not known yet.（主语从句） This place is where they once hid.（表语从句） 4、as作从属连词可引导多种状语从句。 （1）as引导时间状语从句，意为“当…时”。例如：As (he was) a young man, he was a storekeeper and later a postmaster./ He sang as he worked. 高.考.资.源.网 （2）as引导方式状语从句，意为“象…一样”。例如：We must do as the Party teaches us.　 （3）as引导原因状语从句。意为“由于”，例如：As you are tired, you had better rest.　 （4）as引导让步状语从句。意为“虽然”、“尽管”Child as he is, he can do it well. ( = Although he is a child, he can do it well.) 另外，as做为关系代词还可以引导定语从句，如：I have the same book as you. 状语从句练习 【练习一】 1 ( ) 1 The meeting didn't start___ everyone was there. A. because B. until C. why D. if ( ) 2 The boy ___ to bed ___ his mother came in. A. went not; until B. didn't go; after C. went; until D. didn't go; until ( ) 3 I won't believe you___ I have seen it with my own eyes. A. before B. until C. after D. when ( ) 4 He ___ home ___ she was satisfied ___ his answer yesterday. A. didn't go; until; with B. wasn't go; after; to C. doesn't go; before; with D. didn't go; until; to ( ) 5 He ___ back until the work ___ done. A. isn't; will be B. isn't; is C. won't be; will be D. won't be; is ( ) 6 They didn't start the work ___ their teacher came back. A. until B. while C. as soon as D. if 2 ( ) 1 Tom will call me as soon as he ___ Shanghai. A. arrives B. will reach C. arrives in D. get to ( ) 2 I'm sure he'll come to see me before he ___ Beijing. A. will leave B. is leaving C. leave D. leaves ( ) 3 I will tell him the news as soon as he___ back. A. come B. comes C. will come D. came 3 ( ) 1 Tom has got a watch. He ___ it for two years. It _______ by his father. A. has bought; was bought B. has got; is bought , C. was bought; has bought . D. has had; was bought "' ( ) 2 When he got to the station, the train ___. A. left B. had left C. leaves D. has left ( ) 3 The boy told his father what he ___ in the street. A. saw B. have seen C. had seen D. see ( ) 4 We ___ TV when the telephone ____. A. watched; was ringing B. were watching; rang C. watch; rings D. are watching; rang ( ) 5 By the end of last term, I___ ten books. A. had finished reading B. have finish reading C. had finish to read D. finish read 4 ( ) 1 I ___ you for a long time. Where ___ you ___? A. didn't see; did; go B. didn't see; have; gone C. haven't seen; have; been D. haven't seen; have; gone ( ) 2 Tom___ China for 3 years. A. has been B. has been in C. has been to D. has been at ( ) 3 I won't go to see the film tonight, because I ___ my ticket. A. lost B. have lost C. will lose D. didn't lose ( ) 4 -Hello! May I speak to Bob? -Sorry, but he ___ for a month. A. had been away B. was left C. left D. has been away ( ) 5 I ___ him since I began to live in the city. A. know B. have known C. knew D. will know ( ) 6 Zhao Lan ___ already ___ in this school for two years. A. was; studying B. will; study C. has; studied D. are; studying 5 ( ) 1 Betty didn't go to see the film yesterday ___ she was ill. A. because B. but C. until D. if ( ) 2 May I sit nearer___I can see more clearly? A. as if B. so that C. even if D. so ( ) 3 ___ you work hard, you will certainly succeed. A. Though B. If C. Because D. For ( ) 4 ___ he came to study in the university, he has made much progress in the study of English. A. While B. When C. Since D. After ( ) 5 I'd like to go swimming _____ the water is not too cold. A. for B. unless C. if D. whether 6 ( ) 1 There are ___ many league members in class 2 ___ in Class 4. A. both; and B. 'so; that C. either; or D. as; as ( ) 2 -Do you have a big library? -No, we don't. At least, not___yours. A. as big as B. as big than C. as bigger than D. bigger as ( ) 3 Suzhou is not ____ beautiful ____ Hangzhou. A. as; than B. so; as C. even; than D. /; than ( ) 4 Iron is more useful ___ any other metal. A. as B. than C. then D. so 7 ( ) 1 I want to know ___ she is going to see a film. A. if B. that C. what D. which ( ) 2 You are sure to pass the exam ___ you study hard. A. if B. thoughC. that D. since ( ) 3 I'll go to see the film with you___I have time this evening. A. whether B. so C. if D. when ( ) 4 ___ you study harder, you'll never pass the final exam. A. If B. Until C. Unless D. Except 8 ( ) 1 Although it was raining, ----still worked in the fields. A. but they B. and they C. they D. and yet they ( ) 2 ___ there were only five soldiers left at the front, ___ they went on fighting. A. Because; so B. If; and C. Though; but D. Though; / ( ) 3 ___ she is very old, ___ she can still work eight hours a day. A. Because; so B. Though; but C. As; yet D. Though; yet 9 ( ) 1 Please answer the question in a loud enough voice ___ all the class may hear. A. so, that B. or C. in order that D. and ( ) 2 Lift it up___I may see it. A. though B. so that C. as D. than ( ) 3 I hurried___I wouldn't be late for class. A. so B. so that C. if D. unless ( ) 4 We should go by bus ___ we can get there earlier. A. as soon as B. where C. in order that D. as 10 ( ) 1 The dictionary is so expensive ___ I can't buy it. A. because B. when C. that D. if ( ) 2 I got there ___ late ___ I didn't see him. A. too; to B. such; that C. so; that D. so; as ( ) 3 It is ___ hot in the room ___ we have to go out for a walk. A. such; that B. so; that C. as; as D. such; as ( ) 4 He has___ an interesting book that we want to read it. A. so B. such C. the same D. as 参考 答案 八年级地理上册填图题岩土工程勘察试题省略号的作用及举例应急救援安全知识车间5s试题及答案 ： 1. 1-6 B D B A D A 2. 1-3 C D B 3. 1-5 D B C B A 4. 1-6 C B B D B C 5. 1-5 A B B C C 6. 1-4 D A B B 7. 1-4 A A C C 8. 1-3 C D D 9. 1-4 C B B C 10. 1-4 C C B B 一. 单项填空 1. _______ he’s old, he can still carry this heavy bag.   A. Though  B. Since  C. For  D. So 2. ---Do you know if he _______ to play basket ball with us?   ---I think he will come if he ______ free tomorrow.   A. comes; is  B. comes; will be  C. will come; is  D. will come; will be 3. In the zoo if a child _____ into the water and can’t swim, the dolphins may come up ______ him.   A. will fall; to help   B. falls; to help   C. will fall; help     D. falls; helping 4. I don’t remember ________ he worked in that city when he was young.   A. what  B. which  C. where  D. who 5. We will stay at home if my aunt ________ to visit us tomorrow.   A. comes  B. come  C. will come  D. is coming 6. The police asked the children _______ cross the street ________ the traffic lights turned green.   A. not; before  B. don’t; when  C. not to; until  D. not; after 7. I was late for class yesterday _______ there was something wrong with my bike.   A. when  B. that  C. until  D. because 8. I’ll go swimming with you if I ________ free tomorrow.   A. will be  B. shall be  C. am  D. was 9. In the exam, the ________ you are, ______ the _______ mistakes you will make.   A. careful; little     B. more careful; fewest   C. more careful; fewer  D. more careful; less 10. You should finish your lessons _______ you go out to play.   A. before  B. after  C. when  D. while 11. I hurried _____ I wouldn’t be late for class.    A. since  B. so that  C. as if  D. unless 12. When you read the book, you’d better make a mark _______ you have any questions.    A. which  B. that  C. where  D. though 13. The teacher raised his voice _______ all the students could hear him.    A. for  B. so that  C. because  D. in order 14. He took off his coat _______ he felt hot.    A. because  B. as  C. if  D. since 15. It is ______ that we’d like to go out for a walk.    A. a lovely day    B. too lovely a day    C. so lovely a day  D. such lovely a day 16. Mary had ______ much work to do that she stayed at her office all day.    A. such  B. so  C. too  D. very 17. _______ I felt very tired, I tried to finish the work.    A. Although  B. Because  C. As  D. As if 18. ______ the day went on, the weather got worse.    A. With  B. Since  C. While  D. As 19. ______ well you can drive, you must drive carefully.    A. So long as      B. In order that    C. No matter how   D. The moment 20. Write to me as soon as you ________ to Beijing.    A. will get  B. get  C. getting  D. got 【练习答案】 一. 1.A 2.C 3.B 4.C 5.A 6.C 7.D 8.C 9.C 10.A 11.B 12.C 13.B 14.A 15.C 16.B 17.A 18.D 19.C 20.B 实例解析】 1. (2004年北京市海淀区中考试题)   You will stay healthy _______ you do more exercise, such as running and walking.   A. if  B. how  C. before  D. where   答案：A。该题考查的是引导状语从句的从属连词的选择。从意思上看，从句应是一个条件状语从句，在这四个选项中只有if能引导条件状语从句，所以选A。 2. (2004年江西省中考试题)   ---Shall we go on working?   ---Yes, _________ I prefer to have a rest.   A. when  B. if  C. because  D. though   答案：D。该题考查的是引导状语从句的从属连词的选择。从意思上看，只有选though才能说得通。 3. (2004年徐州市中考试题)   None of us knew what had happened _________  they told us about it.   A. when  B. until  C. after  D. though   答案：B。该题考查的是引导状语从句的从属连词选择。本句的意思是“在……以前我们没人知道这件事。”要表达着一意思应用“not…until” 这一句型。 4. (2004年泉州市中考试题)   ---I hope you’ll enjoy your trip, dear!   ---Thank you, mum. I’ll give you a call _________ I get there.   A. until  B. as soon as  C. since  D. till   答案：B。该题考查的是引导状语从句的从属连词的选择。本题的意思是“一到那里，我就给你打电话。”要表达这个意思应选用as soon as。 ［考题1］ I had just steeped out of the bathroom and was busily drying myself with a towel ____ I heard the steps. (2006湖南) A. while B. when C. since D. after ［答案］ B ［解析］ 下划线处表示 “正在这时， 突然……”， 四个选项中只有when可以表示此含义。 ［考题2］ He was about halfway through his meal ____ a familiar voice came to his ears. (2006辽宁) A. why B. where C. when D. while ［答案］ C ［解析］ 下划线处表示 “正在这时， 突然……”， 四个选项中只有when可以表示此含义。 ［考题3］ We were swimming in the lake ____ suddenly the storm started. (2004北京春) A. when B. while C. until D. before ［答案］ A ［解析］ 题意为“当我们正在湖里游泳的时候突然暴风雨开始了”， 表示主句的动作处于从句的动作突然发生时应采用when(while不适合用于这样的语境)， when表示“当……的时候”受限制条件最少。 ［考题4］ — I’m going to the post office. — ____ you’re there, can you get me some stamps? (1999) A. As B. While C. Because D. If ［答案］ B ［解析］ 主句中“get me some stamps”的动作发生在时间状语从句“you’re there”的过程之中， 因此应选while表示这一时间关系(属于while引导时间状语从句的两大基本用法之一)。注意： as有时也可用于表示主句的动作发生在从句动作的过程中， 但这一用法不是as引导时间状语从句的主要用法， 表示主句的动作发生在从句动作的进行过程中时用while更为常见， 因此B选项是最佳选项。 ［考题5］ ____ the days went on, the weather got worse. (1990) A. With B. Since C. While D. As ［答案］ D ［解析］ 表示“the days went on”、 “the weather got worse”两个相互伴随地进行变化的动作， 应选as表示这一时间关系(while不适合用于这样的语境)。 ［考题6］ Tom ____ into the house when no one ____. (1992) A. slipped; was looking B. had slipped; looked C. slipped; had looked D. was slipping; looked ［答案］ A ［解析］ 题干当中的when表示“当……的时候”， slip表示“偷偷地、 悄悄地移动”， 在本题中表示非延续性的动作——“溜进了教室”的结果， 不适合用进行时态表示。第一个下划线处应填入slipped， 以一般过去时客观描述在过去某一时间上发生的动作； look表示延续性的动作， 可以持续进行， 所以第二个下划线处应填入was looking， 以过去进行时描述汤姆溜进教室的大背景。 注意： 如果主句的动作发生于表示“当……时”的时间状语从句中的动作的进行过程中， 从句常用进行时。例如： The landlady suspected that someone must have broken into the house when/while/as she was watching TV show. 女房东怀疑在她看电视时曾有人闯入屋里。 When/While/As Tom was reading, Jim was arrested. 在汤姆看书的时候， 吉姆被逮捕了。 ［考题7］ I ____ along the street looking for a place to park when the accident ____. (2006安徽) A. went; was occurring B. went; occurred C. was going; occurred D. was going; had occurred ［答案］ C ［解析］ 根据题干句子含义， 事故发生于当我沿街行驶、 寻找停车之处的时候； 从句的动作发生在主句动作的过程中。主句的谓语动词go表示非延续性的动作， 可以持续进行， 应选用过去进行时的形式， 从句的谓语动词为非延续性动词， 应以一般过去时的形式表结果。 ［考题8］ He was told that it would be at least three more months ____ he could recover and return to work. A. when B. before C. since D. that ［答案］ B ［解析］ 表示“他康复并返回工作岗位之前至少还需要三个月”， 下划线处应选用before。 ［考题9］ It was some time ____ we realized the truth. A. when B. until C. since D. before ［答案］ D ［解析］ 题干意为： 过了一段时间我们才意识到真相。下划线处应填入表示“在……之前”的连词。 ［考题11］ — Why didn’t you tell him about the meeting? 　— He rushed out of the room ____ I could say a word. A. before B. until C. when D. after ［答案］ A ［解析］ 根据题干中第一句话的提示， 第二句话中的“he rushed out of the room”发生于“I could say a word”之前。 ［考题15］ They ____ the train until it disappeared in the distance. (1998) A. saw B. watched C. noticed D. observed ［答案］ B ［解析］ 题干中的主句为肯定句， until需要跟主句里肯定形式的表延续性动作的谓语动词连用， 因此本题应选表示延续性动作的watched(其他选项中的saw， noticed， observed所表示的动作都不能延续， 意味着结果)。 ［考题16］ —Was his father very strict with him when he was at school? —Yes. He had never praised him ____ he became one of the top students in his grade. (2003北京春) A、 after B.unless C.until D.when ［答案］ C ［解析］ until跟主句里否定形式的、 表非延续性动作的谓语动词连用时， 表示“直到……才(开始)”， 本题应选until与主句中的“never praised”对应， 表示“他的父亲直到他成为年级里的尖子生之一时才开始称赞他”。 ［考题18］ — What was the party like? 　　— Wonderful. It’s years ____ I enjoyed myself so much. (1993) A. after B. before C. when D. since ［答案］ D ［解析］ since表示“自从……以来”。 ［考题19］ They ____ friends since they met in Shanghai. (1989) A. have made B. have become C. have been D. have turned ［答案］ C ［解析］ 题干中的since表示“自从……以来”， 主句中的谓语动词应该表示从他们在上海相遇至今的持续性的动作， 因此下划线处应填入可以表示持续性状态的have been(其他选项中的made、 become、 turned所表示的动作都不能延续， 意味着结果)。 ［考题1］ Small sailboats can easily turn over in the water ____ they are not managed carefully. (2007上海) though B. before C. until D. if ［答案］ D ［解析］ 根据全句意思， “they are not managed carefully”应表示一种假设， 因此下划线处应选用if引导条件状语从句。 ［考题2］ In time of serious accidents, ____ we know some basic things about first aid, we can save lives. (2006重庆) whether B. until　C. if D. unless ［答案］ C ［解析］ 本题应选意为“如果”的if表示假设。 ［考题3］ I would appreciate it ____ you call back this afternoon for the doctor’s appointment. (2003上海春) until B. if C. when D. that ［答案］ B ［解析］ 本题应选意为“如果”的if表示假设。 ［考题4］ It is known to all that ____ you exercise regularly, you won’t keep good health. (2005重庆)A。unless B. whenever C. although D. if ［答案］ A ［解析］ 本题应选意为“如果不， 除非”的unless表示假设。 ［考题5］ Most birds find it safe to sleep in the trees, but ____ they have eggs or young chicks, they don’t use a nest. (2007湖南) A． why B. how C. unless D. where ［答案］ C ［解析］ 综合整句的意思， 下划线处应表示“除非……”含义的假设。 典型例题： 1） ___she is young, she knows quite a lot. A. When　B. However　 C. Although　 D. Unless 答案：C。意为虽然她很年轻，却知道许多。 ［考题1］ We had to wait half an hour ____ we had already booked a table. (2007辽宁) A. since B. although C. until D. before ［答案］ B ［解析］ 下划线处之后所述的“我们已经预订了一桌”与前面所述的“我们已经不得不等了半个小时”之间语意相反， 四个选项中although表示“即便……”， 引导让步状语从句最为合适。 ［考题2］ ____ most of the earth’s surface is covered by water, fresh water is very rare and precious. (2006上海春) A as B. Once C. If D. Although ［答案］ D ［解析］ 句意为： 虽然地球表面覆盖着水， 但是纯净水仍然很稀有、 珍贵。下划线处应引导让步状语从句， 填入although最为合适。 ［考题3］ ____ he has limited technical knowledge, the old worker has a lot of experience. (2006) A. Sinc