造纸术是哪个朝代发明的

若A并B=U,则(CuA)交（CUB）=空集吗? Lizza 这个名字是男生的还是女生的?不一定是英文名 可以是法文或是其他 ---It’s said that Williams will come to help us.--- we depend on him,we have to do most of the work ourselves.A．No matter what B．However much C．Whatever D．However 找出句子并画出语素 语素可以充当句子成分吗? are these your cousin 词汇的最小单位叫语素,比如“咖啡”就是一个语素.为什么? 请问男生16岁还能学拉丁舞吗?体重60Kg, 用rely on it that造句 你可以放心一切将在一周之前准备好（rely on it that)(英文翻译,用上所给词哦） point at是什么意思? point point at的意思, 双水解反应在什么情况下可以进行到底?我知道 铝离子与碳酸氢根能双水解,因为生成的 氢氧化铝 二氧化碳 可以脱离反应体系,所以可以进行到底.那为什么 铵根与醋酸根反应 生成 醋酸 氨气 It's safe for you to stay at home.改为同意句 at which It's safe for you to stay at home.改为同意句 You ___It's safe for you to stay at home.改为同意句 You _____ _____stay at home. 某地在汛期前一天测得主要河道水位是6.4米,在之后的半个月中,每天测得水位较前一天的变化如下（单位：米,水位上升记为正）：-0.3,+0.2,+0.5,-0.2,+0.8,+0.4,+0.3,-0.1,0,-0.36,+0.4,+0.4,-0.1,-0.5,-0.3.若当 什么是CREST analysis C,R,E,S,T分别代表什么 fine,thanks,andyou,怎么回答 O.T.S的电子手表背面的W.R啥意思 某堰塞湖水位已达到64cm,假设湖堤底部能承受的最大压强是7乘10的⑤次方Pa,那么水面最多还能升几米? 已知水位达到64米,假设杯底能承受的最大压强是7*10的五次方Pa,那么水面最多还能上升几米?如题 英语作文 检查很简单的narrative paragraph.求检查一下sentence structure,时态,还有一些语句通顺之类的,总之看不顺眼的都请指出! Zick Friehiet什么意思?名字帮查！ zick 1.Did you f__ with others yesterday.2.We ___ carefully,but we can ____ nothing.A.looks;see B.watches;sees C.looks;see D.look;see3.Mary felt terrible.Now she is ___.A.in bed B.on bed C.in the bed D.on the bed 4.You can't watch TV.(改为祈使句）__ 选 择 ------ her carefully ,but I --- --nothing .见下面补充A hear listin B listin hear C listin to hear D hear listin to I listened carefully but I heard nothing各个单词在句中起什么成份? 帮忙检查一下这片英语作文（急）初一英语My favourite petMy favourite pet is a mouse. He is my pet.He is about 1 years old.We called him Dumpling,because he is quite fat.He has grey-and-black fur.His paws is pink.He has two big black 三个字的句子有哪些比如说 我爱你 对不起 我错了 像这样的3三个字的句子... 句子中含有叶世和雨这三个字