从两栖动物的生殖发育对环境的要求，解释为什么两栖动物的数量在急剧减少？我们应当采取哪些保护措施（至少3个）？-生物

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• “稻花香里说丰年，听取蛙声一片．”雄蛙的鸣叫有利于青蛙的繁殖______．-生物
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• 下列动物中生殖发育离不开水域环境的是（）A．家鸽B．蟾蜍C．家兔D．壁虎-生物
• 某科研小组在研究蛙的生长发育过程时，发现了生活在某山区中的个别青蛙发育过程如图．利用所学知识请回答下列问题：（1）该山区的土壤，饮水和食物中缺碘，使生活在该环境中的部-生物
• “黄梅时节家家雨，青草池塘处处蛙”，雄性青蛙鸣叫的目的是[]A．招引雌蛙B．寻找食物C．练习发音D．逃避敌害-八年级生物
• 下图为形态结构、生活习性互不相同的几种动物，请分析回答：（1）在生物分类上，上述五种动物所属最大共同单位是。（2）动物的分类除了要比较外部的形态结构，往往还要比较动物的-八年级生物
• 对蛙的受精卵孵化条件的叙述，合理的是[]A．没有成体的保护，所有的受精卵将无法孵化B．所有的受精卵在孵化过程中都需要一定的条件C．所有的受精卵在孵化过程中的营养物质一定来-八年级生物
• 青蛙从幼体到成体，不可能出现的变化是[]A．鳃消失B．尾消失C．体表出现鳞片D．长出四肢-八年级生物
• 下列哪项不属于青蛙的生殖行为[]A．雄蛙的鸣叫B．雌雄青蛙的抱对C．雌青蛙产卵D．蝌蚪变成青蛙-八年级生物
• 青蛙的发育过程与家蚕的发育过程的相同点是①变态发育②经过蛹期③将卵产生水中④有性生殖[]A．①③B．①④C．②③D．②④-八年级生物
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• 青蛙的生殖方式是[]A．有性生殖B．无性生殖C．孢子生殖D．分裂生殖-八年级生物
• 两栖动物的生殖和幼体发育必须在水中进行，幼体要经过变态发育才能到陆地上生活。[]-八年级生物
• 下列哪一项不是成蛙的特征[]A．能在水中游泳B．能够生活在陆地上C．能用鳃呼吸D．能用肺呼吸-八年级生物
• _____ Mr. Rowan Atkinson acts as different comic characters, he is more famous around the world ____
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• 短文改错。此题要求改正所给短文中的错误。对标有题号的每一行作出判断；如有错误（每行只有一个错误），则按下列情况改正：该行多一个词：把多余的词用斜线（\）划掉，在该行右边-高二英语
• I'm your class today so you must doI tell you. [ ]A. instead of, what B. in the form of, like C
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• 短文改错。此题要求改正所给短文中的错误。对标有题号的每一行做出判断：如无错误，在该行右边横线上画一个勾（V）；如有错误（每行只有一个错误），则按下列情况改正：此行多一个-高一英语
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• 、连线题（4分）动物能进行各种有利于个体生存和繁殖的活动。请将以下相关的内容连线。-八年级生物
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• 青蛙的个体发育过程是（）A．雌雄同体、体内受精B．雌雄同体、体外受精C．雌雄异体、体内受精D．雌雄异体、体外受精-八年级生物
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• 下列能正确表示蛙的发育过程的是A．受精卵——蝌蚪——幼蛙——成蛙B．受精卵——幼蛙——蝌蚪——成蛙C．卵细胞——蝌蚪——幼蛙——成蛙D．卵细胞——幼蛙——蝌蚪——成蛙-八年级生物
• 青蛙不能成为真正陆生动物的原因是A．体温不恒定B．生殖离不开水C．皮肤辅助呼吸D．变态发育-八年级生物
• _____ school work, I spend most of my spare time singing and dancing.[ ]A. Together with B. In terms