在生态系统中，有毒物质能够沿着食物链逐渐积累。[]-七年级生物

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• 下图为生态系统物质循环过程，请据图填写。①____________②_________③__________④__________A__________B__________C__________-八
• 组成生物体的物质在________________之间的往返循环就是生态系统的物质循环。-八年级生物
• —The room is so dirty. _____ we clean it? '—Of course.[ ]A. Let'sB. Would C. DoD. Shall-七年
• We'll get there at eight, but they _____.[ ]A. aren'tB. didn'tC. won'tD. don
• 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
• 当食草动物摄取食物时，植物体内的能量就会全部流入动物体内。[]-八年级生物
• 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
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• 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
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• 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
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• 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
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• 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.[
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• 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
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