在生态系统中的物质和就是沿着食物链和食物网流动的。-七年级生物

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• Your mother looks a bit disappointed. You have told her the truth. [ ]A. doB. must C. can D. want-九年
• —_____ I do the laundry first?—No, you _____. You can do your homework first.[ ]A. Must;mustn't
• _________是生态系统的能量来源。能量流动是从__________开始，其特点是__________。-八年级生物
• Mr. Green ______ speak a little Chinese, but he can't speak any Japanese.[ ]A. can B. may C. mu
• 某湖泊生态系统中，湖水中的DDT相对浓度为0.5×10-6，现发现各生物体内均有不同浓度的DDT，检测结果如下：检测对象ABCDEDDT浓度/×10-60.0052.00.575.50.04（1）5种
• 下表是对5种生物体内农药含量的测定结果，这些生物与生物之间有着吃与被吃的关系，请你分析，下列哪一条食物链的联系是正确的生物种类ABCDE单位体积农药含量（毫克）0.0450.-七年级生物
• —You fly the kites very well.—Thank you. I________ kites when I was 7 years old.[ ]A. can flewB. cou
• It's raining hard outside, so they stay in the classroom.[ ]A. must B. can C. have to D. might-
• 用情态动词can， may， must的适当形式填空。1.—What _______ I do for you? —I want some apples.2.My father _______ride
• 生物的下列过程中，与碳循环无直接关系的是[]A．光合作用B．呼吸作用C．微生物分解作用D．蒸腾作用-八年级生物
• 下列是温带草原上的部分生物：A．植物B．鼠C．蛇D．鹰E．食虫鸟F．植食昆虫，它们通过食物形成的联系如下图。（1）请根据你掌握的知识把以上生物的代号填人方格内。（2）生态系统的四种-七年级生物
• 生态系统中，有毒物质通过食物链会________（填“增加”、“减少”或“不变”）。-七年级生物
• —Can you come to Susan's party? —Sorry. I ________ look after my grandma.[ ]A. amB. have to C.
• -Must we clean the classroom now?-No, you _____.[ ]A. mustB. needn'tC. aren'tD. must not-八
• -Listen! Is that Kate playing the piano inthe room?-No. It _____be Kate. She has gone to London.[ ]A
• I _______ like some noodles.[ ]A. does B. hadC. would -九年级英语
• 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
• 按要求完成句子。1. She can help you. (改为否定句) She ______________ you.2. He would like to play basketball with
• 施用农药DDT的地区，虽然占陆地面积的一部分，可是在远离施药地区的南极，动物体内也发现了DDT，这种现象说明了[]A．DDT是挥发性物质B．南极动物也偶尔到施用农药的地区寻找食-八年级生物
• 某湖泊中存在着4种不同的生物A、B、C、D。研究者对其体内的食物成分进行了分析，并将结果绘制成下表：请你回答。（1）根据上表提供的信息，以食物链的形式表示4种生物的取食关系-七年级生物
• 从“狼吃羊，羊吃草”看出，狼体内有机物最终来源于[]A．狼B．羊C．草D．光-七年级生物
• 图反映了生态系统各成分之间的相互关系，据图分析回答下列问题：（1）图中①的作用是制造__________，因此，①被称为生态系统中的__________。（2）图中消费者是标号[]和标号[]所示-七年
• —Could you play football with me this afternoon?.—I'm sorry. I babysit my sister.[ ]A. have toB
• You _______ drive on the left in Hong Kong.[ ]A. can B. mustC. have toD. do-八年级英语
• This dictionary mustn't _____from the library. Youcan only use it here. [ ]A. take awayB. taken
• -_I finish my homework today, Mum?-No, you _ . You can do it on Saturday. [ ]A. Must; don't hav
• -Will you go to the party with us?-I'm not sure, I ___ go to visit my grandma with my cousin.[
• —Must I return the book tomorrow? —No, you _____. You _____ keep it for a few days. [ ]A. mustn'
• — _______ you come to our piano lesson?—Sure. I'd love to.[ ]A. Are B. Do C. CanD. Must-八年级英语
• 生态系统中的能量最终都来自于_________。-八年级生物
• Henry ________ be at home because he phoned me from the farm just now.[ ]A. mustn'tB. might not
• — Where's Lucy, please?— She_____ be in the library.[ ]A. canB. needC. could D. may-九年级英语
• —_ you get some milk for me?—Sure.[ ]A. MayB. MustC. ShouldD. Could-八年级英语
• —_____you play the piano?—No. But I can play the violin.[ ]A. CanB. MayC. MustD. Should-八年级英语
• —Where is your father now?—I'm not sure．He _______ be in the kitchen． [ ]A. mayB. mustC. will D
• I can play basketball, but my sister _____. [ ]A. hasn'tB. can'tC. doesn't D. isn
• —Can you come to have dinner with me this evening? —I'm afraid not. I _______ take care of my g
• Jeff can't come to the party, because he'llhelp his sister with the housework.[ ]A. must B
• 大气中的_________是碳循环的主要形式。-八年级生物
• You_____ right.[ ]A. may beB. maybeC. can be-八年级英语
• Both of his parents died of illness so he support his family at the age of 14. [ ]A. mustB. shouldC.
• _____he is in reading room now. [ ]A. MaybeB. May be C. May-八年级英语
• —____I come in?—Comein ,please.[ ]A. MayB. MustC. NeedD. Have to-八年级英语
• The teacher gave back his homework, so he_ do it again.[ ]A. mustB. had toC. needed D. might-八年级英语
• —_________ you play golf ?—No. But I can play table tennis.[ ]A. Can B. May C. Must D. Should-八年级英语
• —You _____ be very tired after the long flight. —Yeah, though I am tired, I feel excited and happy.[
• 生态系统中的能量流动伴随着__________。-八年级生物
• Youkeep the book for a week.[ ] A. can B. have to C. must D. should-八年级英语
• Cathy said shespeak four languages.[ ]A. mayB. couldC. wouldD. can-八年级英语
• You________ be careful when you are driving atnight.[ ]A. can B.should C.wouldD. could-八年级英语