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请问,当用大理石与稀硫酸反应制二氧化碳时,会生成可溶物(微溶物?)硫酸钙附在大理石表面阻止反应进行.用大理石与稀盐酸反应,会生成氯化钙(好像也是可溶物),为什么后者不停止反应 高三化学复习要注意什么? 初级社会群体的主要功能. 1987年,美国科学家将萤火虫的萤光素基因转入烟草植物细胞,获得高水平的表达.长成的植物通体光亮,堪称自然界的奇迹.这一研究成果表明 ①萤火虫与烟草植物的DNA结构基本相同 ②萤火虫与 能提高良种家畜繁殖能力的细胞工程是...答案是胚胎移植...为什么?我认为是细胞核移植(因为这样优良的性状得以保留) 硫酸钡是不是沉淀 化学反应速率和活化能的测定实验中,求活化能时温度用什么单位 硫酸钙是沉淀吗在离子方程要当成沉淀吗？ 硫酸钙在化学方程式中写沉淀吗 英语改错!（一定要说原因!、）the doctrine of popular democracy,which practiced in Greece in the fourth century B.C.,had spread to the far reaches of the earth in the mid-twentieth century.Moses,an Israelite leader and prophet,died just be 英语改错,并说出原因.1.The man smiled pleasant and told her how to get there.2.Mary is sitting among her mother and her father.3.She greeted me warm and we talked a lot about her family.4.He did very good this afternoon.5.I gave him a glass o seo2,so2和h20反应生成单质硒的化学方程式 加热蒸馏烧瓶需要垫石棉网吗? 加热蒸馏烧瓶需要垫石棉网吗 硫酸钙是不是沉淀 硫酸钙是沉淀吗_初中阶段问题 1)已知一次函数y=kx+b(k,b是常数).变量x与y的部分对应值如下表:的解是 英语改错 还有详细的原因Boys and girls,in age 5-16,who preferred leisure activities is watching TV or videos,which is 100% 英语改错（说理由）1.Having worn out after along walk,Helen called and said that she could not come to the party.2Most of students,surprising at the way the question was put,did not know how to answer it.3Everything taking into considerration 一个关于热力学第一定律的问题一个矩形封闭容器,上端是用不计摩擦的质量为M的板盖住的,上板距离下底面的距离为H,现在吸收热量Q后上板上升,稳定后与下底面距离为D+H,那么气体的内能增 英语单词填空＋改错A terrible tsunami s____ Southeast Asia in 2004,causing great losses.You will have to ask p____ from the chairman if you want to leave the meeting early. 高中英语单词拼写及改错单词拼写1.The vase is broken.The cleaner who in the the room then said that Jim was to____(责备）2.That man is not dead.He is just____(熟)asleep3.He used to get his milk from the____(牛奶厂)every day4.He is 分别概述三次科技革命对资本主义社会发展的影响 英语单词改错Sandy may is able to dance .We all don't know when is the lesson given.请写出答案和理由 几次科技革命的影响说明了什么? 英语单词改错（急!帮帮忙!）Mike spends about three hours to play computer games every day.If robots do all the houseworks for us, we'll have more free time to relax.My teacher told me cleaned the classroom after class.There will have a 三次科技革命对世界格局的影响~三次科技革命都引起了世界格局的变化,请任选其中的两次科技革命分别说出他们对世界格局的影响? 英语单词改错(快一点)1.My brother always sleeps while the windows open.2.Mario works hardly and he is good at his lessons.3.She wouldn't mind to take place care of our children.4.Great changes take place in China in the last few years.5.There 请推荐一些关于论述科技革命本身以及影响的书籍 请教热力学第一定律适用问题这道题选的是D,我做的另一道题选了B,我觉得不需要恒压微分式也是成立的,只是如果去掉微分就只能选D了…… 请教热力学第一定律的写法问题是因为功和热都不是状态函数吗? 如何除去反应中生成的氨气和氢气我要制取气体,可反应中有氢气生成,且必须通入过量的氨气,我该怎么办?