红磷燃烧

怎样选择电阻丝 功率怎么计算 液压泵的选择计算,功率和效率计算例题：在一个线路牵引施工现场中,根据设计要求,牵引力F为15t时,牵引速度υ应能达到2.5km/h.是为此牵引机液压系统选择合适的液压泵. uPs 如何计算功率,选择 A bed,a desk and a chair () in the room.()是 is 还是 are I like swimming in the river .（把主语换成he ) There is a desk in the room .（改为复数句子） How many chair are there in the room?There is a chair in the room.但问的时候是复数喔.答得时候是单数. There () a desk and a chair in the room.括号里面,是填is还是 为什么呢?There () a desk and a chair in the room.括号里面,是填is还是 为什么呢? go on holiday,holiday前要不要加a 去度假是用go on a holiday还是go on holiday? All the tasks _______ahead of time ,they decided to go on holiday for a week.A had been filled B having been filledC were filled D been filledwhy 英语度假是go for holiday还是go on holiday 为什么go on holiday,go for a holiday一个有冠词,一个无冠词 压铸模具投影面积和压铸机吨位怎么计算?各位；我计算出铸件的投影面积A1为165005（平方毫米）,浇道A2为A1*0.2=33001,料柄A3为3.14*70*70=15386,排溢系统A4=A1*0.15=24750,S=A1+A2+A3+A4=238142.然后F涨型力=K( 压铸机和冲压机怎样根据吨位计算每小时用电量 求my faourite sporting hero英语作文80字左右!最好是写王励勤的 把这些句子改成复数形式：1、where is the newspaper?2、is there a child in the room?3、is that person your friend?4、who is that woman? 英语作文《My Hero》,写肖邦的,80词左右. There is one child left a____ in the room There is a child in the classroom变成复数句子 元素周期表,最好能速记!不要说一下子就忘掉的那种! 化学元素周期表有什么简单容易背的方法么 what about __ a rest after such a long walk A、to take B、takes C、taking D、takewe should learn to __ (节约) our pocket moneythe girl did very __ (bad) in the high jump.my grandfather got __ (lose) last sunday afternoon. 怎么背元素周期表相对简单点? ---What about__a rest?---Ok.Let's go out and have a walk.A.to take B.takes C.taking D.to taking -What about ( )(take) a rest? -Ok.请问应该怎样填? What about all of us----[take】 a rest take的正确形式about后面接了all of us对于take的形式有影响吗？ What about+doing?后面加名词ing? There is a baby in the room.改疑问句和否定句 急求,一篇英语作文my hero,八十词,希望是近代的人物.当代也ok啊. 一道单项选择：There is a baby ( A ) in the roomA :crying C :cried C为什么不对 my hero 英语作文 60字要介绍他的出生日期 自己为什么喜欢他 还要学习他什么精神 What about taking a walk?（改为同义句） How about （ ）（ ）（ )(