下列关于生态平衡的叙述，正确的是[]A．生态系统一般不会出现平衡状态B．生态平衡意味着生态系统中各种生物的数量恒定不变C．破坏生态平衡的主要原因是恶劣的自然条件D．生态系统-八年级生物

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• In China，a lot of food is wasted every year and the waste food is enough for people. The food is was
• -Hello, _______ I speak to Lily? -Hold on, please.A．mayB．must C．needD．should-八年级英语
• ______ I have a quick word with you? Something important has happened.A．MustB．CouldC．WouldD．Should-九
• --- ________ have you kept the book ? --- Since last Month. I ________ return it to the library tod
• Can you play tennis ? --_______A. No , he can’t B. Yes , I can C. No, I’m not-七年级英语
• Few weight-loss pills can help to keep people slim, _______?A．do theyB．dodt theyC．can't theyD．
• If you _____ smoke, please go outside.A．canB．mayC．mustD．might-八年级英语
• 下列对生态系统的叙述正确的是[]A．最大的生态系统是海洋生态系统B．为了保护羊而把狼全部抹杀掉，这对草原生态系统没有影响C．人类的生产活动过度不会破坏生态系统的自动调节能-八年级生物
• 如果人类大量捕杀鹰，草原生态系统将受到严重破坏，这说明[]A．生态系统无调节能力B．生态系统的调节能力是无限的C．只有绝对禁捕野生动物，生态系统才有调节能力D．生态系统调节-八年级生物
• _______ you tell me how I_______ get to the No．168 Middle School?A．Do；canB．Can；couldC．Could；canD．Cou
• I ________ be a little bit slow, but at least I don’t make foolish mistakes. A．shouldB．mayC．mustD．ne
• ---Mum, could I go shopping with you? --- Yes,________ . But you have to finish your homework first.
• - Youeat the soup if you don’t like it.A．shouldn’tB．mustn’tC．can’tD．needn’t-九年级英语
• For the safety, everyone _________ obey the traffic rules when he is driving or walking.A．needB．must
• ----Jack, how are you feeling now?----I am much better, Mum, so you ______________ take me to see th
• — Who’s that boy reading in the garden? Is it David?— It ____________ be David. I saw him in the cla
• -May we leave the classroom now?-No, you _______. You _______ to leave until the bell rings.A．can�
• Look at the “No parking” sign. You _____park your car here.A．shouldB．mustC．needn’tD．mustn’t-八年级英语
• ——Hate cannot drive out hate; only love ___________do that.——Martin Luther King, Jr.A. can B. must C
• 下列对于生态平衡理解正确的是[]A．生态系统中各种生物数量保持相等B．生态系统中各种生物数量保持不变C．生态系统中各种生物数量保持相对稳定D．生态系统中各种生物数量不断变化-八年级生物
• 洞庭湖某棉产区，在较早些年由于瓢虫、草蛉、蚜寄蜂等棉蚜天敌的控制，使害虫棉蚜数量一直维持在较低水平，没有造成棉花减产，但是后来由于长期不合理使用有机杀虫剂，天敌被-八年级生物
• —_____I bring my ID card with me next time?—No, you needn’t. I have copied and stored it in my compu
• —Will you please answer the door? It ________ be your sister.—Sorry, I ________. I’m feeding the rab
• —Is this Toby’s iPhone5，Jenny ?—No，it________be his. His is black A. muctn’t B. can’t C. may not. -九
• - It took me nearly 40 minutes to ride here.- Have a drink, please. You _________ be thirsty.A．willB
• I’m feeling much better now, so you call the doctor.A．couldn’tB．wouldn’tC．can’tD．needn’t-八年级英语
• A: Listen! Is it Tina singing in the next room?B: No, it __________ be her. She is still in Shanghai
• Mike, please be quiet, or the other students hear me clearly.A．mustn’tB．shouldn’tC．needn’tD．can’t-七
• — ____ you sing the English song?— Yes, I can.A．CanB．MayC．MustD．Need-七年级英语
• After you read the article “Why fast food is slowly killing you”, youstop eating fast food. A．canB．
• ---Is the man over there Mr. Brown?----It ______ him. He has gone to Brazil to watch the 2014 FIFA W
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• 我国南方某些地区建立了“桑基鱼塘”农业生态系统，获得了鱼、猪、蚕和粮食全面丰收。下图是该生态系统的物质循环和能量流动示意图，据图回答：（1）该生态系统所需要的能量来自。-八年级生物
• —I was asked to attend the meeting before eight.—Oh, you________. I'm sorry for not telling you
• ---Few young people in China know about Lady Gaga , _______?---_______, she is quite famous here in
• Must we finish all the homework today or tomorrow?– You ____ worry about it. You may hand it in next
• — __________ we leave the library before 5 o’clock?— No, you needn’t. You can stay here until 5:30.
• - Tom, where is your father?- I’m not sure. He _______ in his office.A．must beB．may beC．maybeD．need
• --- Whose backpack is this?--- It be Mary’s. She is looking for hers.A．canB．mustC．mayD．can’t-八年级英语
• A hard-working man become a great scientist, but a great scientist be a hard-working man.A．can’t; ca
• "Whose T-shirt is this?" "It_____ be John's. It's much too small for him.”A
• —What will the weather be like tomorrow?—It _______ be rainy, cloudy or sunny. Who knows?A．mustB．mig
• --Must we stay in the classroom and finish all the homework?--No, you______. You can take it home.A．
• — Who’s that man over there standing in the garden? Is it Mr. White?—It __________ be him. He has go
• -Must I send my uncle an e-mail now, Dad? -No, you ____.You____ do that after you finish your homew
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• —Would you like to watch the 2014 Nanjing Youth Olympic Games this summer holiday?—I’d love to. I be
• -----Look !Sue is over there.----That _________be her .She is in Canada now.A .mustn’t B. can’t C. n
• 下面短文中的划线部分都是错误的，请改正。并将正确答案写在右边相应题号的横线上，多余的请用斜线划掉，不得改变原文意思。Many Chinese people are try to improve the