rna聚合酶作用部位

一个长方体,长和宽尺寸不变,高减少2厘米后就变成一个正方体,这样长方体的表面积就减少48平方厘米,原来这个长方体的长、宽、高各是多少? 一个正方体的表面积是24平方厘米,把它切成两个同样大小的长方体,这个长方体的表面积是（ ）平方厘米,体是多少（ ）立方厘米.要列式,要说原因. 1.现有1000t含Fe2O3的铁矿石,问可以炼多少吨纯铁?2.已知化合物HnRO2n-1(2n-1为右下角角标)相对分子质量为M.求(1)R化合价 (2)R相对原子质量?（3）原子团RO2n-1(2n-1为右下角角标)化合价?3.4.6g某物质在 70吨含氧化铁60‰的铁矿石中含铁元素多少吨? 很多美国人用英语说有复数吗? i hope to buy some presents for my family and friends 不是说hope+sb+todo不能修饰人吗? she went to buy some tickets for boating for her classmates.为何不用to sb.而用for sb. 一根圆柱形钢管截成4段,表面积增加了75.36平方厘米,这根钢管的底面半径是多少厘米?怎么半径不是3厘米啊 底面半径是4厘米,高是6厘米,求表面积 长21宽14的缸 需要多大功率的过滤器?3W的够用么? 一个圆柱,表面积是345.4平方厘米,底半径是5厘米,求它的高. 50的小缸到底用什么样的过滤器好点呢,现在有个挂式过滤但是效果不好,还有加热棒用多大的,主要过滤水中杂物,急 如何除去铁矿石中的SiO2 如何将bought,friends,pesents,for,my,during,I,the,hoildays,some连词成句? 连词成句bought my l for presents friends 连词成句,1.bought,griends,presents,for,my,during,l,the,holidays,some2.better,is,year,arunner,than,Danny,this,year,last,3.of,is,school,the,Wendy,our,best,jumper,in,one,4.fun,Sports,do,and,let's,have,in,best,Day,our, A great man once said it is necessary to dill as much as possible,andthe more you apply it in real dill 充当什么成分? Once an old man went to see a doctor.The doctor looked him over carefully and said,“Medicine won怎么写 Once an old man went to see a doctor.The doctor looked him over carefully and said,““Medicine won’t help you.You must have a good rest.Go to bed early,drink milk,walk a lot and smoke one cigar a day.Go to the country place for a mouth.”After a man once said how useless it was to put advertise 阅读理解A man once said how useless it was to put advertisements in the newspapers."Last week,"he said,"my umbrella was stolen from a London church.As it was a present,I spent twice its worth in 烷烃中是否包括甲烷?烷烃分子中是碳原子与碳原子间以碳碳单键结合成链状的烃,那么只有一个碳原子的甲烷是不是属于烷烃哪?烷烃分子中是碳原子与碳原子间以碳碳单键结合成链状的烃， 1\The experienced merchant made a( ) that I would get into trouble doing business with a companylike that.A suggestion B decision C forecast D trend 2\The old man knows nothing about the matter( )what he has read in the newspaper.A over B below Cwith it is said that e-schoolbags are going to be brought into use in chinese midddle schoolsbe brought into use 如何理解 I want to give some cartoons for my friends.改错 请说出原因为什么这样改. 生物膜结构面积一个高等的完整植物细胞（含叶绿体和中心液泡）的膜面积是单层细胞膜面积的几倍?您说的那些我都知道，就是说有没有测量过的一个大约值？那啥，夏夜之灵你的答案没有 I want to buy Simon some presents 改为同亿句 生物膜结构包括啥? 人的唾液细胞中面积最大,分布最广泛的膜结构是?A：细胞膜 B：内质网 C：核膜 D：高尔基体 那个能把雅安市雨城区的地质地貌,地下水、地层构造等告诉小弟我谢谢 急用我要做一个勘察投标书 那个大大有雅安地区的地勘报告可以发给我一个 我QQ就是我名字谢谢 塑料培养瓶需不需要铺明胶?是不是只是玻璃培养瓶才需要? 如何创新明胶配方?最近公司进口了一批明胶,想在这个明胶配方基础上进行创新,不知道哪家公司比较有经验? 养细胞用过的装明胶(1%gelatin)的玻璃瓶如何清洗?本人养细胞用过的装明胶(1%gelatin)的玻璃瓶无论是用水冲,还用胰酶洗,又用开水煮30分,都冲洗不掉内壁上面的明胶,