生态系统是指下列哪两种成分彼此作用而构成的一个统一整体（）A．生产者和消费者B．生产者和分解者C．生物和非生物环境D．生产者和环境-生物

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• Tom and I good friends. [ ]A. is B. am C. are D. be -七年级英语
• If prices rise too high, the government has to do something _________ it. A．stopB．stoppedC．stoppingD
• 选择填空。The little girl ______ afraid of the dogs. [ ]A．doesn't B．isn't C．can't -七年级英语
• — Can I go to the movie, Mum? — Certainly. But you be back by ten o'clock. [ ]A. can B. may C.
• ______ you don’t give up, your dreams will come true. A. As long asB. As soon as C. As well as-九年级英语
• —______ I put the bike here?—No, you can't.[ ]A. MayB. MustC. NeedD. Shall-八年级英语
• 如图为民谣“螳螂捕蝉，黄雀在后”所描述的生态系统中各种成分之间相互依存的关系图，请据图回答：（1）绿色植物、细菌、真菌和其他三种动物组成了生态系统中的______成分；（2）请-生物
• 如图表示某个生态系统中各种成分之间的关系，图中的①所代表的成分名称是（）A．生产者B．消费者C．分解者D．非生物的物质和能量-生物
• —What's in the reading room?— There a teacher, twenty desks and thirty chairs in it. [ ]A. am B
• There ____ a pen, a ruler and two books on the desk. [ ]A. is B. are C. aren't D. am -七年级英语
• 单项选择。Look at the monkeys. ______ they cute? [ ]A．Isn't B．Aren't C．Don't -七年级英语
• 单项选择。—How much ______ the blue socks? — They ______ only one dollar. [ ]A．is, are B．are, isC．are, ar
• Where ______ the post office? [ ]A. are B. is C. does D. do -七年级英语
• — Who’s singing in the next room?— It ____ be her . She has gone to New York.A．can’tB．mustC．shouldn’
• —Must I go with them tomorrow?—No, you . A. mustn’t B, shouldn’tC. needn’t D. can’t-九年级英语
• That young woman _____a teacher. She looks very graceful.[ ]A. may be B. can beC. must beD. won'
• “神舟”七号宇宙飞船顺利返航，三位宇航员除了把生活用品包装带回地球外，他们的尿液、粪便也要一并带回．这是因为太空中（）A．缺乏分解者B．没有消费者C．缺乏空气D．温度太低-生物
• If you _____the book, you ____ buy it right now, I think.A．needn’t, needn’tB．don’t need, don’t needC
• 单项选择。Lily and Linda ______ good friends. [ ]A. amB. isC. are D. be -七年级英语
• “花草”在生态系统中扮演的角色是（）A．消费者B．生产者C．分解者D．非生物部分-生物
• 改错。1. My favorite subject is math and English. 2. Why do she like music best?3. What's you favo
• —How many students are there in your school?—the students in our school over two thousand. A．The num
• 如图是某草原生态系统中的食物网示意图，请根据图回答问题．（1）在此生态系统中青蛙和蜘蛛除了捕食关系外，还有______关系．（2）在草原生态系统的组成中，图中未画出的生态系统的-生物
• —Peter doesn’t mind lending you his camera.—He __________. I’ve already borrowed one.A．needn’tB．can’
• 选择填空。 Where ______ Bob and Tom ______? [ ]A. is; from B. do; comes C. are; from D. does; from -七年级英语
• 选择填空。______ you from England? [ ]A. Are B. Do C. Where D. How -七年级英语
• 地理中国栏目报道：广西某地最近突然出现了一条“变色河”，该河大多河段清澈见底，唯独在靠河岸某处呈黄褐色；不久之后，该处黄褐色会逐渐消褪，却又在较远的河中央开始出现．（-生物
• 梅花山是国家级森林和野生动物自然保护区．梅花山生态系统中的非生物因素包括（）A．生产者B．消费者C．分解者D．空气、水分、阳光-生物
• Tom has grown enough to take care of.A．tall; himB．tall; himselfC．old; himD．old; himself-九年级英语
• 墨西哥湾漏油事件发生后，中美科学家发现了一种能“吸食”石油的细菌．这种细菌属于（）A．生产者B．消费者C．分解者D．消费者和分解者-生物
• 选择填空。Yesterday ______ my little brother's third day to school. [ ]A. is B. was C. are D. be -七年
• Nanjing isn’t so large __________ Shanghai, however, it’s the second __________ city in East China.A
• 在生态系统中，绿色植物属于（）A．生产者B．消费者C．生物部分D．非生物部分-生物
• 硫细菌能利用化学能将无机物转变为有机物，这类细菌在生态系统中属于（）A．生产者B．消费者C．分解者D．消费者和分解者-生物
• The final exam is coming. Our teachers tell us _____ time. A. not to waste B. not waste C. don’t was
• When I was a child, my grandmother _____ me interesting stories. A. used to tell B. is used to telli
• – Whose notebook is this? -- It _____ Tom. I saw he used it just now. A. must belong to B. can’t bel
• 选择填空。Who ______ the women in the picture? [ ]A. is B. are C. be D. am -七年级英语
• You ______ wear sports shoes when you climb a mountain.A．can’tB．shouldn’tC．mustn’tD．have to-九年级英语
• 下列关于生产者的叙述中，正确的是（）A．生产者是在自然界中不依赖外界环境，能独立生存的生物B．生产者的营养方式肯定是自养C．生产者中绝大多数为自养，少数为异养D．生产者的再-生物
• 生态系统的能量是沿着食物链依次流动的．一般说，一个环节只能把所获得能量的约______传递给下一个环节，也就是说，能量的流动具有______特点．生态系统的稳定性是指生态系统经-生物
• ―______ you born?―In a town near Tianjin. [ ]A. When wereB. Where did C. Where were D. Where was -八年
• 生态系统的营养结构基础是（）A．生产者和分解者B．食物链和食物网C．物质和能量D．空气和水-生物
• 生物圈中的动物必须直接或间接地以______为食，通过消耗绿色植物合成的______来维持生活，所以，动物是生物圈中的______．-生物
• 细菌属于生态系统中的______，其生殖方式是______．-生物
• 句型转换，每空一词。1. They're used for seeing in the dark. (改为否定句)Theyfor seeing in the dark. 2. Liu Wei
• The number of teachers in our school _______ greatly increased last term.A number of teachers in thi
• My sister has practiced tennis for a long time. She plays tennis _____ you. A. as good as B. so well
• —________ I smoke here?—No. You are not allowed to smoke in public places.A．CouldB．MustC．MayD．Might-
• 近年来，我国大力开发建设西部地区．要求西部地区切实搞好生态环境保护，退耕还林，治理水土流失，防止沙漠化等．据此回答下列问题：（1）从生物学角度分析，改善西部生态环境，首-生物