Unit 4 Wildlife protection The first period Warming up Knowledge aims: a. help Ss to understand and master the words and expressions in warming up b. Let the students know some basic information about the endangered animals and wildlife situation and protection ability aims: Encourage Ss to think and express their attitude towards the wildlife and the wildlife protection Emotional aims: a. Help Ss understand the importance of the wildlife protection and make them be more active in the helping wildlife b. Develop Ss'sense of cooperative learning Teaching Key Points: Enable the students to know some basic information about the endangered animals and wild life protection Encourage Ss to think and express their attitude towards the wildlife and the wildlife protection Teaching difficult points: How to enable the students express themselves freely Teaching Materials Blackboard, multi-media, and other normal teaching tools Teaching methods Co-operative learning Students-centered approach Task-based teaching and learning Teaching procedures: Step 1: Lead-in Lead in by explaining the title and predicting what will be learned in this lesson. Step 2: Exploration Task: let the students explore the following question What is the problem of wild animals commonly facing? 1. Show some pictures to the students. Students watch the pictures and say what the pictures tell us References: food shortage, pollution, destruction of habitat, over-hunting 2. Show the students three more pictures and ask: what do people kill or hunt these animals for?
Unit 4 Wildlife Protection The first period Warming up Knowledge aims: a. help Ss to understand and master the words and expressions in warming up. b. Let the students know some basic information about the endangered animals and wildlife situation and protection. Ability aims: Encourage Ss to think and express their attitude towards the wildlife and the wildlife protection. Emotional aims: a. Help Ss understand the importance of the wildlife protection and make them be more active in the helping wildlife. b. Develop Ss’ sense of cooperative learning. Teaching Key Points: Enable the students to know some basic information about the endangered animals and wildlife protection. Encourage Ss to think and express their attitude towards the wildlife and the wildlife protection. Teaching Difficult Points: How to enable the students express themselves freely. Teaching Materials: Blackboard, multi-media, and other normal teaching tools. Teaching methods： Co-operative learning Students-centered approach & Task-based teaching and learning Teaching Procedures: Step 1: Lead-in Lead in by explaining the title and predicting what will be learned in this lesson. Step 2: Exploration Task: let the students explore the following question: What is the problem of wild animals commonly facing? 1. Show some pictures to the students. Students watch the pictures and say what the pictures tell us. References: food shortage, pollution, destruction of habitat, over-hunting. 2. Show the students three more pictures and ask: what do people kill or hunt these animals for?
From these pictures, students can conclude that people kill animals for food, for fur for med icine and for works of art 3. Ask the students to give their answers to the question: What is the problem of wild animals commonly facing? Step 3: Discussion 1. Let the students discuss the following question: why should we pay attention to wild animals and plants Students discuss the question in groups and then give their opinions 2. After discussion, tell students what is wild life protection about Step 4: Group work 1. Let the students read the report on some endangered wildlife in China at page 25.SB sk the students some questions about the report 3. Let the students describe the chart in small groups accord ing to the sample 4. Discussion. More and more animals are killed by humans, as a student what should you do to protect the wild animals? Step 5: Homework Write a composition accord ing to the tips 假如你是一名记者,采访某动物园负责人有关国宝大熊猫的情况。下面是采 访要点,请根据谈话要点为《中国日报》写篇专题报道。内容如下: 熊猫是世界上的稀有( scarce))动物,人们非常喜欢它。 2很久以前中国有很多熊猫,但由于生态遭到破坏,加上天气变暖,熊猫越 来越少了 3现在中国大熊猫的数量每年都在增加,其中一些已经送到国外供人们观赏。 4目前中国最大的熊猫自然公园在四川。这里有一个野生动物研究中心,熊 猫的生长就是在这里研究的。科学家们希望有一天能够有足够的熊猫可以放 出去,让它们重新生活在旷野中。 The second period Reading l知识目标 1) Get the students to learn about some endangered animals and the knowledge of wildlife protection 2) Enable the students to use some key words and phrases to talk about wildlife protection 2能力目标 1) Get students to understand the passage by using different reading skills 2) Enable the students to talk about wildlife protection and know the importance of wildlife protection 3情感目标
From these pictures, students can conclude that people kill animals for food, for fur, for medicine and for works of art. 3. Ask the students to give their answers to the question: What is the problem of wild animals commonly facing? Step 3: Discussion 1. Let the students discuss the following question: why should we pay attention to wild animals and plants. Students discuss the question in groups and then give their opinions. 2. After discussion, tell students what is wildlife protection about. Step 4: Group work 1. Let the students read the report on some endangered wildlife in China at page 25, SB. 2. Ask the students some questions about the report. 3. Let the students describe the chart in small groups according to the sample. 4. Discussion. More and more animals are killed by humans, as a student what should you do to protect the wild animals? Step 5: Homework Write a composition according to the tips. 假如你是一名记者，采访某动物园负责人有关国宝大熊猫的情况。下面是采 访要点，请根据谈话要点为《中国日报》写篇专题报道。内容如下： 1.熊猫是世界上的稀有（scarce)动物，人们非常喜欢它。 2.很久以前中国有很多熊猫，但由于生态遭到破坏，加上天气变暖，熊猫越 来越少了。 3.现在中国大熊猫的数量每年都在增加，其中一些已经送到国外供人们观赏。 4.目前中国最大的熊猫自然公园在四川。这里有一个野生动物研究中心，熊 猫的生长就是在这里研究的。科学家们希望有一天能够有足够的熊猫可以放 出去，让它们重新生活在旷野中。 The second period Reading 1.知识目标 1）Get the students to learn about some endangered animals and the knowledge of wildlife protection. 2）Enable the students to use some key words and phrases to talk about wildlife protection. 2.能力目标 1）Get students to understand the passage by using different reading skills. 2）Enable the students to talk about wildlife protection and know the importance of wildlife protection. 3.情感目标
1) Enable the students to learn about the importance of the wildlife protection and learn what we should do to protect the wildlife from dying out 2)Develop the students'sense of cooperative learning Teaching important points 1. Get the students to learn about some endangered animals and the knowledge of wildlife protection 2. Enable the students to use some key words and phrases to talk about wildlife pr Teaching difficult points How to enable the students to grasp the main idea of the text quickly Teaching methods rative learnin 2. Activity-based teaching(individual work; group work; class work) 3. Students-centered approach Task-based teaching and learning Teaching aids: Blackboard, multi-media, and other normal teaching tools Teaching procedures:(教学过程) Step 1: Pl I Lead in by a song. 2. Warming-up Show the students some pictures of endangered animals After the students watching the pictures, let them know that if we dont ta measures to protect endangered animals, they will die out Step 2: While-reading Scanning Let the students read the text quickly to learn something about Daisy's journey and then fill in the blanks Animals she met Places she went First visit antelope Tbet Second visit elephant Zimbabwe Third visit monkey rainforest 2. Detailed reading. Let the students read the text carefully to find out more details about Daisys journey. Before read ing each paragraph, show them tasks Para 1: the antelope -libet Task one: Skimming. Find out the answers to the following two questions from
1）Enable the students to learn about the importance of the wildlife protection and learn what we should do to protect the wildlife from dying out. 2）Develop the students’ sense of cooperative learning. Teaching important points: 1. Get the students to learn about some endangered animals and the knowledge of wildlife protection. 2. Enable the students to use some key words and phrases to talk about wildlife protection. Teaching difficult points: How to enable the students to grasp the main idea of the text quickly. Teaching methods: 1. Co-operative learning 2. Activity-based teaching (individual work; group work; class work) 3. Students-centered approach & Task-based teaching and learning Teach in g aid s: Blackboard, multi-media, and other normal teaching tools. Teaching Procedures: （教学过程） Step 1: Pre-reading 1. Lead in by a song. 2. Warming-up Show the students some pictures of endangered animals. After the students watching the pictures, let them know that if we don’t take measures to protect endangered animals, they will die out. Step 2: While-reading 1. Scanning Let the students read the text quickly to learn something about Daisy’s journey and then fill in the blanks. Animals she met Places she went First visit antelope Tibet Second visit elephant Zimbabwe Third visit monkey rainforest 2. Detailed reading. Let the students read the text carefully to find out more details about Daisy’s journey. Before reading each paragraph, show them tasks. Para 1: the antelope --Tibet Task one: Skimming. Find out the answers to the following two questions from
para 1 Q1: How does the antelope feel? Q2: What situation is it in? Para 2: the elephant-Zimbabwe Task one: Skimming. Find out the answers to the following two questions from para 2 quickly Q1: How does the elephant feel now? Q2: What situation is it in now? Para 3: the monkey Task one: Skimming. Find out the answers to the following two questions from para 3 quickly Q1: How does the monkey feel? Q2: What situation is it in? Step 3: Post-reading 1. Self-exploration Let the students explore the following question by watching three pictures Why are these animals endangered? 2. Discussion What should we do to protect the wildlife? Let the students discuss and a few minutes later, report the results Step 4: Summary and homework 1. Sum up the whole lesson by showing the waning *Killing animals is killing ourselves Lets leave our children a living planet 2. Homework. What you have learned in this unit? verbs 2. useful ad jectives 3. useful expressions 小结 The third period Vocabulary and useful Expressions
para 1 quickly. Q1: How does the antelope feel? Q2: What situation is it in? Para 2: the elephant -- Zimbabwe Task one: Skimming. Find out the answers to the following two questions from para 2 quickly. Q1: How does the elephant feel now? Q2: What situation is it in now? Para 3: the monkey Task one: Skimming. Find out the answers to the following two questions from para 3 quickly. Q1: How does the monkey feel? Q2: What situation is it in? Step 3: Post-reading 1. Self-exploration Let the students explore the following question by watching three pictures: Why are these animals endangered? 2. Discussion What should we do to protect the wildlife? Let the students discuss and a few minutes later, report the results. S tep 4: Summary and homework 1. Sum up the whole lesson by showing the warning: *Killing animals is killing ourselves ! *Let’s leave our children a living planet ! 2. Homework. What you have learned in this unit? 1. useful verbs_____________________________________________________. 2. useful adjectives________________________________________________. 3. useful expressions_______________________________________________. 小结________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________. The third period Vocabulary and Useful Expressions
Teaching important points To let students master the pronunciation of the new words and phrases To let students know the main usages of them Teaching difficult points How to help students master the pronunciation within limited time How to make the usages clear. Teaching procedure Step 1. Greeting Step 2. Daily report Step 3. New words and phrases learning 1. The whole class read the new words and phrases together following the teache 2. Let students read them aloud by themselves for a while 3. Explain the usages of the words and expressions as follows ① protection n.保护 ② protect vt.^sh. from/against.保护…避免 He's wearing the sunglasses to protect his eyes from/against the strong sunshine ③ as a result结果A句 As a result,B句 I got up late this morning. As a result, I could catch the first bus as a result of= because of为介词词组,不能引导句子 He was late as a result of getting up late ④ die out灭亡;逐渐消失 Milu deers are dying out ⑤ loss n His sacrifice is a loss of our country
Teaching important points To let students master the pronunciation of the new words and phrases. To let students know the main usages of them. Teaching difficult points How to help students master the pronunciation within limited time. How to make the usages clear. Teaching Procedure Step 1. Greeting Step 2. Daily report Step 3. New words and phrases learning 1. The whole class read the new words and phrases together following the teacher. 2. Let students read them aloud by themselves for a while. 3. Explain the usages of the words and expressions as follows: ① protection n. 保护 ② protect vt. ~sth. from/against…保护……避免…… He’s wearing the sunglasses to protect his eyes from/against the strong sunshine. ③ as a result 结果 A 句.As a result, B 句. I got up late this morning. As a result, I could catch the first bus. as a result of= because of 为介词词组，不能引导句子。 He was late as a result of getting up late. ④ die out 灭亡；逐渐消失 Milu deers are dying out. ⑤ loss n. His sacrifice is a loss of our country
at a loss不知所措 without a loss毫无保留 make up a loss补偿损失 a forest reserve保护林 reservation n.预定;保留 ⑦ hunt vt They are hunting the pro oper person vi hunt for/after iEi The lion is hunting for the monkeys go hunting去打猎; a job hunting找工作 ⑧ zone n.地区;地带;区域 time zone a danger zone the war zone 9 peace n. peaceful adj. peacefully=in peace adv The Chinese live in peace after liberation (10 in danger-out of danger 1 The little girl is in danger because she has fallen into the river. However, she is out of danger now with the help of the army. 11. stomach n I feel painful in my stomach stomachache n.胃痛; headache n.头疼; apply for申请 I will apply for the job in the company apply to sb. for sth向某人申请 I will apply to my boss for a better saraly apply oneself to专心于 The diligent girl applies herself to study. 13. thick-thin 14 contain v
at a loss 不知所措 without a loss 毫无保留 make up a loss 补偿损失 ⑥ reserve n. a forest reserve 保护林 reservation n. 预定；保留 ⑦ hunt vt. They are hunting the proper person. vi. hunt for/after 追逐 The lion is hunting for the monkeys. go hunting 去打猎；a job hunting 找工作 ⑧ zone n. 地区；地带；区域 time zone, a danger zone, the war zone ⑨ peace n. peaceful adj. peacefully=in peace adv. The Chinese live in peace after liberation. ⑩ in danger- out of danger ⑪ The little girl is in danger because she has fallen into the river. However, she is out of danger now with the help of the army. 11. stomach n. I feel painful in my stomach. stomachache n. 胃痛； headache n. 头疼； 12. apply vi. apply for 申请； I will apply for the job in the company. apply to sb. for sth.向某人申请…… I will apply to my boss for a better saraly. vt. apply oneself to 专心于…… The diligent girl applies herself to study. 13. thick – thin 14. contain vt
包含 This book contains information that you need 容纳 This room can contain56 students The drug is harmful to people's health the drug store药房; take the drug吃药 16. affect vt. This movie deeply affects me effect n. have an effect on; have a good/bad effect on The computer game has a bad effect on students'study side effect副作用 This kind of med icine has side effect 17. attention n draw/get/attract/catch one's attention吸引某人的注意力 That handsome boy attracts/catches/draws/gets her attention fix/ focus ones attention on sth.讲精神、注意力集中于 They fix/focus my attention on that handsome guy pay attention to sth Please pay attention to what I said just now come into beir Do you know when the humans came into being? 19. dust n The ground is full of dust dusty adj.有尘的;多尘的 20. recently adv Recently, I haven t seen the poor woman 21. fie Lion is fierce animal
包含 This book contains information that you need. 容纳 This room can contain 56 students. 15. drug n. The drug is harmful to people’s health. the drug store 药房；take the drug 吃药 16. affect vt. This movie deeply affects me. effect n. have an effect on; have a good/bad effect on The computer game has a bad effect on students’ study. side effect 副作用 This kind of medicine has side effect. 17. attention n. draw/get/attract/catch one’s attention 吸引某人的注意力 That handsome boy attracts/catches/draws/gets her attention. fix/focus one’s attention on sth. 讲精神、注意力集中于…… They fix/focus my attention on that handsome guy. pay attention to sth. Please pay attention to what I said just now. 18. come into being Do you know when the humans came into being? 19. dust n. The ground is full of dust. dusty adj. 有尘的；多尘的 20. recently adv. Recently, I haven’t seen the poor woman. 21. fierce adj. Lion is fierce animal
22. lazy adj. laziness n. (happy- happiness Don t be so lazy since the exam is coming Step 4. Homework Review the new words and expressions 小结 The fourth period grammar Teaching aims Let students get used to Passive Voice in different tenses Teaching difficult point How to help students master the usages of passive voice in different tenses Teaching procedure Step 1. Greeting Step 2. Daily Report Step 3. Introduce Passive Voice 语法:被动语态 主动语态与被动语态的概念: 英语动词的语态有两种:(1)主动语态:表示主语是动作的执行者 (2)被动语态:表示主语是动作的承受者(常常没在有必要指出动作的执行者情 况下使用) 例: They speak English.(主动语态) 主谓 English is spoken by them(被动语态) 主 谓 介词短语 注:及物动词有被动语态,不及物动词必须带有介词才可以有被动语态 f : (1)We listen to the teacher carefully in class 主谓 -The teacher is listened to by us carefully in class 谓介词短语 (2)We laughed at him He was laughed at by us
22. lazy adj. laziness n. (happy- happiness) Don’t be so lazy since the exam is coming. Step 4. Homework Review the new words and expressions. 小结：________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________. The fourth period Grammar Teaching aims Let students get used to Passive Voice in different tenses Teaching difficult point How to help students master the usages of passive voice in different tenses Teaching Procedure Step 1 . Greeting Step 2 . Daily Report Step 3 . Introduce Passive Voice 语法：被动语态 一、 主动语态与被动语态的概念： 英语动词的语态有两种：⑴主动语态：表示主语是动作的执行者 ⑵被动语态：表示主语是动作的承受者(常常没在有必要指出动作的执行者情 况下使用) 例：They speak English. （主动语态） 主 谓 宾 English is spoken by them. （被动语态） 主 谓 介词短语 注：☆及物动词有被动语态，不及物动词必须带有介词才可以有被动语态。 例：⑴We listen to the teacher carefully in class. 主 谓 宾 →The teacher is listened to by us carefully in class. 主 谓 介词短语 ⑵Ｗe laughed at him . → He was laughed at by us
二、被动语态的结构与用法: ()结构:be+done(过去分词) 被动语态中的be为助动词,无意义。be可能是am,is,are也可能是was,were 或原形be。 注:☆被动语态的时态是由be的时态决定的,be是什么时态,全句就是什 么时态,be后面的过去分词不变。 (用法 例:① History is made by the people.(一般现在时) ② The cars were made in Tianjing in1995(一般过去时) ③ The tree will be cut down next year(一般将来时) ④ T he room must be kept clean.(含有情态动词的被动语态) 5The door is being opened.(现在进行时) ⑥ The film has been seen by me.(现在完成时) 被动语态的各种句型 1、 The song is liked by young people.(肯定句) 2、 T he song isn't liked by young people(否定句) 3. Is the song liked by young people 般疑问句) 4、 Who is the song liked by?= By whom is the song liked?(特殊疑问句) 四、主动语态改被动语态的方法 方法分为三步:(1)把原句中的宾语改成主语 (2)动词改为变动形式 be done(同时注意时态) (3)原来的主语如果需要的话放在介词by后面,以指明做的 人或物,如果没有必要则省去 例: The man killed a tiger → A tiger was killed by the man(改的过程中要注意时态和语态两个方面) 五、特殊句型的被动语态: (1)含有使役动词( make /let /have)或感官动词(hear,see, listen to look at,find, watch,fel等)的句子,在主动语态中这些词后常跟不带to的动词不 定式,但是在改成被动语态时,则一定要把省去的to再加上去,另外help 这一个词在主动语态中后面的动词不定式可以带to,也可不带to,但在被动语 态中也必须把to加上去 例:① Mother often makes me do some housework +I am often made to do some housework by mother. 2We saw him run into the classroom He was seen to run into the classroom by us (2 ) teach give,pass,show,buy,tell等动词常常带有两个宾语(双宾语:直接宾 语和间接宾语),改为被动语态时,两个宾语可以选其中任一个作主语。如果 直接宾语被提前作主语,那么间接宾语(一般是人)前要加相应的介词to/fors
二、 被动语态的结构与用法： ㈠结构：be +done (过去分词) 被动语态中的 be 为助动词，无意义。be 可能是 am , is , are 也可能是 was ,were 或原形 be。 注：☆被动语态的时态是由 be 的时态决定的，be 是什么时态，全句就是什 么时态，be 后面的过去分词不变。 ㈡用法： 例：①Ｈistory is made by the people. (一般现在时) ②Ｔhe cars were made in Tianjing in 1995. (一般过去时) ③The tree will be cut down next year.(一般将来时) ④Ｔhe room must be kept clean. （含有情态动词的被动语态） ⑤The door is being opened. （现在进行时） ⑥The film has been seen by me. （现在完成时） 三、 被动语态的各种句型： １、 Ｔhe song is liked by young people. (肯定句) ２、 Ｔhe song isn’t liked by young people （否定句） ３、 Is the song liked by young people ? （一般疑问句） ４、 Who is the song liked by ?=By whom is the song liked? （特殊疑问句） 四、 主动语态改被动语态的方法： 方法分为三步：⑴把原句中的宾语改成主语 ⑵动词改为变动形式 be done(同时注意时态) ⑶原来的主语如果需要的话放在介词 by 后面，以指明做的 人或物，如果没有必要则省去 例：The man killed a tiger. → A tiger was killed by the man .(改的过程中要注意时态和语态两个方面) 五、 特殊句型的被动语态： ⑴含有使役动词（make /let /have）或感官动词（hear ,see, listen to ,look at ,find ,watch, feel 等）的句子，在主动语态中这些词后常跟不带 to 的动词不 定式，但是在改成被动语态时，则一定要把省去的 to 再加上去，另外 help 这一个词在主动语态中后面的动词不定式可以带 to,也可不带 to, 但在被动语 态中也必须把 to 加上去。 例：①Mother often makes me do some housework. →I am often made to do some housework by mother. ②We saw him run into the classroom. →He was seen to run into the classroom by us. ⑵teach ,give ,pass ,show ,buy, tell 等动词常常带有两个宾语（双宾语：直接宾 语和间接宾语），改为被动语态时，两个宾语可以选其中任一个作主语。如果 直接宾语被提前作主语，那么间接宾语（一般是人）前要加相应的介词 to/for
例:① s he gave me a pen= She gave a pen to me → I was given a pen by her +a pen was given to me by her. @My father bought me a new bike. My father bought a new bike for me I was bought a new bike by my father a new bike was bought for me by my father (3)由不及物动词(v)+介词剧词+宾语的句子改成被动语态时,介词或副 词不能丢掉。(前面已举过两例) 例:① We should speak to old people politely -Old people should be spoken to politely( by us) ② He took away the box -The box was taken away by him (4)含有宾语补足语的句子改为变动语态。(宾补放在原来位置不变) 主谓宾 宾补 -He is called Xiao Ma by us (2He found the book very interesting +The book was found very interesting by him 六、没有被动语态的动词 1.没有被动语态的词,表示状态或特征的及物动词如cost,fit,have,suit 等没有被动形式,另外,诸如 happen= take place, break out(爆发), break down(坏了)等不及物动词或短语以及诸如 result from(缘于), belong to consist of等只用主动语态,而不用被动语态 2不及物动词或动词短语无被动语态: appear, die, d isappear,end(vi结束 fail, last, lie, remain, sit, spread(1#H ) stand, come true, fall asleep 3大多数系动词:be,fel(摸起来), sound(听起来,look(看起来), smel闻起来) taste(尝起来)等词无被动语态,它们的主动形式表示被动意 义 例:① T he skirt feels very soft.这件裙子摸起来很柔软。 @2Many changes have happened in our hometown The film lasted for 3 hours Step 4. Pr 1. I'll be going to work on foot while my bicycle------ (a)is being repaired (b)is repaired (c)will repaired d)has been repaired 2. The radar sets------for a long time without any trouble (b) have been run (c)have run (d )were running
例：①Ｓhe gave me a pen.= She gave a pen to me. →I was given a pen by her. →A pen was given to me by her. ②My father bought me a new bike.= My father bought a new bike for me. →I was bought a new bike by my father. →A new bike was bought for me by my father. ⑶由不及物动词（vi）+介词/副词＋宾语的句子改成被动语态时，介词或副 词不能丢掉。(前面已举过两例) 例：①Ｗe should speak to old people politely. →Old people should be spoken to politely ( by us). ②He took away the box.. →The box was taken away by him. ⑷含有宾语补足语的句子改为变动语态。（宾补放在原来位置不变） 例：①We call him Xiao Ma. 主 谓 宾 宾补 →Ｈe is called Xiao Ma by us. ②He found the book very interesting. →The book was found very interesting by him. 六、没有被动语态的动词： 1. 没有被动语态的词， 表示状态或特征的及物动词如 cost, fit, have, suit 等没有被动形式，另外，诸如 happen = take place, break out(爆发)，break down(坏了) 等不及物动词或短语以及诸如 result from(缘于)，belong to, consist of 等只用主动语态，而不用被动语态 ２不及物动词或动词短语无被动语态: appear, die ,disappear, end (vi. 结束), fail, last, lie, remain, sit, spread（传播）, stand, come true, fall asleep, ... ３.大多数系动词：be , feel (摸起来)，sound(听起来)，look(看起来)， smell(闻起来) taste（尝起来）等词无被动语态，它们的主动形式表示被动意 义。 例：①Ｔhe skirt feels very soft. 这件裙子摸起来很柔软。 ②Many changes have happened in our hometown. ③The film lasted for 3 hours. Step 4. Practise. 1. I’ll be going to work on foot while my bicycle------. (a) is being repaired (b) is repaired (c) will repaired (d) has been repaired 2. The radar sets------for a long time without any trouble. (a) have been running (b) have been run (c) have run (d) were running