农田中除草的目的是[]A．调节农田中生态系统的结构B．调节农田中生态系统的物种C．调节农田中生态系统的能量流动D．A和B-八年级生物

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• 右图表示生态系统各成分间的关系，A、B、C表示生态系统的生物部分，请据图分析回答：（1）若A、B、C包括地球上所有的生物，则该图所示生态系统称为________。（2）图中A表示的是_-八年级生物
• 松树中学生物兴趣小组开展生态系统及稳定性的探究。探究目的：初步学会观察和研究人工生态系统。实验材料：带瓶塞的透明玻璃瓶、凡士林、金鱼藻、绿萍、虾、螺蛳、细沙、河水、-八年级生物
• —Where is our English teacher? —He hasn't come to school today.I think he______be ill.[ ]A. has
• —Must I finish watering the flower, now? —No, you _____. [ ]A. mustB. won't C. needn't D.
• —Mum, must I finish my homework right now?—Oh, you_____.[ ]A. mustn't B. needn't C. can�
• 在生态系统中，组成生物体的化学元素，从__________开始，经__________、__________、_________，又回到________，就完成了一个循环过程，我们称之为生态系统的物质
• 我国南方建立的“桑基鱼塘”模式，是现代农业的典型，该模式获得了鱼、蚕、桑、沼气的全面丰收。请据图回答：（1）在该生态系统中，蚕与桑是______关系。（2）鱼进行生命活动的能量-八年级生物
• 生态系统中的物质循环是[]A．反复出现B．单向流动C．逐级递减D．逐级增加-八年级生物
• 生态系统中能量流动的特点是[]A．双向流动，逐级递减B．单向流动，逐级递增C．循环流动，前后不变D．单向流动，逐级递减-八年级生物
• —How does Shelia get to school? —I don't really know.She______the bus.[ ]A. might takeB. takesC
• —______ you find your math book?—Yes, I can.[ ]A. Does B. AreC. DoD. Can-七年级英语
• "Must I come to see you again?" "No, you _______." [ ]A. mustn't B. can
• You _____be hungry already-you had lunch only two hours ago! [ ]A. wouldn't B. can't C. mu
• —Need I put some milk into the coffee? —No, you.[ ]A. can't B. needn't C. mustn't D.
• — Whose skirt is this?— It the little girl's, I saw her wear it this morning. [ ]A. can be B. c
• 下图表示生态系统的能量流动，请据图回答：（1）生产者是____，初级消费者是____，次级消费者是____，三级消费者是____。（2）图中a1代表_______________________，图中
• 生态系统中的能量最终来源于_______。-八年级生物
• —can you go swimming with us this afternoon?—Sorry, I can't.I______ do the chores at home.[ ]A.
• —______ I keep the magazine a little longer?—Yes, you can. [ ]A. Must B. Need C. Can D. Should -九年级英
• 某校兴趣小组的几位同学，通过对当地某生态系统的观察，绘制出了该生态系统部分生物间的食物关系（见表），请结合所学知识回答：（1）植物是生态系统成分中的；（2）从物质循环的角-八年级生物
• —_____ I use your ruler, Lingling?— Sure. Here you are. [ ]A. May B. Would C. Need D. Must -九年级英语
• 为什么说绿色植物在碳循环中具有重要作用？-八年级生物
• 下图是一个简单的淡水生态系统，请回答：（1）此生态系统中共有__________条食物链。（2）作为一个生态系统，除图中已有成分外，还需要有___________________。（3）流经这个生态系
• “一山不容二虎”这句话，用生态学观点可理解为[]A．虎的生活空间大B．虎不喜欢群居C．身强力壮的虎以身体弱小的虎为食D．虎从食物链中获得的能量少，个体数量少-八年级生物
• 用could, can, may, must, needn't填空。1.A: _______you answer the question in English?B:Sorry, I____
• You ________ knock at the door. Just come in. [ ]A. don't have toB. can't C. mustn'tD
• —Excuse me, is this the right way to No. 1 Middle School?—Sorry, I'm not sure. But it ______ be
• 下图表示某草原生态系统各成分之间的关系。请据图回答下列问题：（1）图中的植物是生态系统中的____________者，动物是生态系统中的___________者。（2）通过食物链和食物网，生态-八年级
• —Is Mr Zhou in the office?—No, he_______ be there.He has gone to Huanggang.[ ]A. mustn't B. nee
• 如图是处于平衡状态的某草原生态系统的食物网。请据图分析回答下列问题（1）这个食物网由_____条食物链构成。（2）此草原上的所有生物及其生活环境共同构成______。（3）对猫头鹰而-八年级生物
• “狼吃羊、羊吃草”，狼体内的能量最终来源于[]A．狼B．草C．羊D．光-七年级生物
• The talented boy _________ write lyrics when he was at the age of ten. [ ]A. may B. could C. must -九
• —Must I finish the work today?—No, you _______.You_______ finish it tomorrow.[ ]A. mustn't, mus
• Could you please _______the laundry?[ ]A. didB. doC. to doD. doing-八年级英语
• Here is a beautiful dress. The owner________ be a boy.[ ]A. mustB. can'tC. mightD. could-九年级英语
• -Who is the woman that is washing clothes? Is it your mother?-No, it _______be her. She is much thin
• -Whose book is this?-It _________ be Li Ping's because there is his name on it.[ ]A. mustB. may
• Itbe my cap.Look, it has my name _it. [ ]A. must; onB. can; in C. must; in D. can; on-九年级英语
• 生态系统中的能量最终都来自于______。-八年级生物
• —Ming _____ row a boat when he was ten. —And he still _____ now. [ ]A. can’t; can’tB. could; couldn’
• You ______ draw on the wall. We must keep it clean. [ ]A. can B. should C. shouldn't D. could -
• It _____ belong to Alice. She plays the guitar. (可能……) [ ]A. can'tB. must C. could -九年级英语
• —Can you come to my party on Wednesday? —Sorry, I can't. I_______finish my homework. [ ]A. mayB
• 在生态系统中，将二氧化碳释放到大气中的过程是[]A．吸收作用B．光合作用C．蒸腾作用D．呼吸作用-八年级生物
• 下列说法中，错误的是[]A．在生态系统中，二氧化碳是碳循环的重要物质B．当动物以植物为食后，植物体内的能量就全部流入到动物体内，供动物生长的需要C．没有绿色植物，自然界的-八年级生物
• —Who's that woman standing near the library? Is it your English teacher Miss Green?—It ______.
• 下图表示生态系统中物质循环的全过程，请据图回答下列问题。（1）碳在无机环境与各种生物之间以_______的形式进行循环。（2）图中的①是指_________（填生理过程），完成过程①的生物-八年级生物
• —_______ you hear me, Ann?—Yes, but not clearly. [ ]A. WillB. CanC. Must D. May-九年级英语
• -Will you stay for supper?-Sorry, I __________.My sister is coming to see me.[ ]A. shouldn'tB.
• 有些细菌，在有氧的条件下能够使污水净化，其原因是[]A．将污水中的有机物分解成二氧化碳和水B．将污水中的病毒杀死C．将污水中的有害细菌杀死D．将污水中的无机物转变成有机物-八年级生物