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1.下列物质中,属于同素异形体的是,A.O2和03 B.CO 和CO2 C.12C和13C D.CH4和C2H62.下列物质中,常温下呈液态的是,A.I2 B.MgCl2 C.Br2 D.SO23.下列物质中,属于酸性氧化物的是,A.H2O B.MgO C.CO2 D.Fe2O3（二）A、B、C 下面的化学题答案是什么,为什么不用其它试剂鉴别①Na2CO3②KCl③Zn(NO3)2④CuSO4四种溶液,先直接鉴别出一种,再逐一鉴别出其余物质,则鉴别的正确顺序是( )A.①④③② B.④①③② C.④②①③ D.① 在CO和CO2的混合气体中,含氧元素百分之六十四,将混合气体5克,先通入灼热的氧化铁中.再通入足量的石灰水中,可得白色沉淀物多少克?希望有才之人能指点下,把具体步骤写下, Na₂S₂O₃•5H₂O(海波)常用下法制备：亚硫酸钠溶液与硫粉共热,生成Na₂S₂O₃,滤去硫粉,浓缩冷却滤液,即有Na₂S₂O₃•5H₂O析出,常混有Na₂SO₃ 化学第22题,谁能帮我逐一解释下. 题如下已知A,B常温下为液态,C,G为单质,医疗上用F来配制生理盐水.A在一定条件下反应下生成B和CD和E反应生成F和BJ和K分别与D反应都生成B,F和I,化学式J中的组成元素比K多一种1.写出E的化学式（ 制取氧气后,集气瓶上盖好玻璃,瓶口向上的原因 本人只有五分,全给!某元素R单质有3种双原子分子,其相对分子质量分别为70,72,74,这3种分子在自然界的物质的量之比为9：6：1,则R元素有多少种核素?其单质的平均相对分子质量为多少? 在标准状况下,1体积水里溶解了500体积的氨气,所得氨水的密度0.9g/cm3,求氨水的摩尔密度（保留一位小数） 第三问和第五问? 化学大题一道.22.（8分）一定温度下,碳与水蒸气在容积不变的密闭容器中发生反应并建立化学平衡：C(s)+H2O(g) CO(g)+H2(g)；△H＞0⑴平衡混合气体的平均相对分子质量M1的取值范围为 ＜M1＜ ⑵将 1.改错You would do a much better work than we would.(我把"a"删去了,不知对否)2.改为感叹句：It's snowing very heavily.（）（）it is snowing!3.改为感叹句：It is great fun to have a pinic on the hillside.() () it is to have a p 英语题 5（最好讲解一下） 求助五道外语题望得到解释11 I _______at the thought of having to make a speech in the presence of all my teachers.a shook b fainted c trembled d declined key c 12 No bread eaten by man is so sweet as __________earned by his own labor.a whi The general’s command was that the soldiers _________ their fort and carry out more important tasks.A.would leave B.leaveC.left D.have leftWritten applications should be sent to us in case _________some problems with the electric version.A.there wi 1.I lost my way in complete darkness and,___ matters worse,it began to rain.A.made B.making C.to make D.having made2.--Can I help you?---I'd like to buy a present for my father's birthday.____ at a proper price but of great use.A.one B.the one C.whic 三道英语题、要解析的1.The doctor did what he could （ ） the dying man. A.saveB.to saveC.saved D.saving2.It's too hot. Put the fish in the fridge ,or it will( ) bad.A.goB.changeC.feelD.keep3.-Will you piease ( ) it to me on Firday? 帮忙做三道英语题（带讲解的）1.My deskmate ,Lily, has been admitted to shan dong university ,learning French, _______ , of course, made the others envy her.A.which B.as2.John got beaten in the game, ______ had been excepted.A.as 英语题III ,请讲解一下 1.-----You look a bit painful.Can I give you a hand -----______,that hurts!A.Get me off B.Don't trouble meC.You needn't do that 2.Grandmother and Penny,the dog,quickly became very attach to each other,but that the attachment grew much____about three 英语题 需解释The construction of the laboratory _ by the end of next monthA must be completed B.musthave been completed C.will be completed D.will have been completing其他的怎么排除的答案是aD怎么错了？？？ 求4,5题答案 4.5.. 第5题过程 第5题的过程 第5题, 谁会第5题的过程呀, 4、5题. 出5道类似的题目, 第五题! 第五题!要写过程!详细! 第5题并且要过程