迈腾280作业

设等差级数的首n项的和是2n + 3n的平方,试求其第r项. 2n=n的平方-3n 怎么解快 古今中外的科学家,音乐家,物理学家等对“时间”的认识 I dislike------me by my first name A.your calling B.you call C.you to call D.calling cousin planned to stay in my home ___A in two daysB for two daysC during two daysD after two days I dislike-----me by my first nameA.your calling B.you call C.you to call D.calling It means "Danger".应该用单引号还是双引号 级数（(-1)^n）/(3n+1) （n从0到无穷）的值?可能要用到幂级数的性质. I miss you too,my confidante 中文意思? Miss.Qi.I will miss you The same to you 求个造句 大气层和太阳比哪个更热? For more than two months,the sun never ______ and there is no light.A.rises B.goes up C.comes upD.goes down 英语翻译Unit.6I went to the plant and spent about a weeklooking around and making notes.I was really amazed at what I saw.Mostcurious of all,there was no quality control whatsoever.No one inspected thefinal products of the factory.As a result som 物价上涨 英语缩写CPI Working hard?直接做疑问句有何道理? He will be missed是什么意思 You will be bette 是什么意思 下列对实验现象的描述正确的是?为什么?A.在硬水中滴入肥皂水会产生浮渣B.紫色石蕊试液使盐酸变红 represent 造句, represent的造句l represented that the bag l had sold is real.这句话写得对吗?represent解释为声称时可以加that从句吗? represent 表示代表时,怎么造句 如何人工制造磁场,如果用铜线做成螺旋状两端接通电源不是会造成短路吗?怎么会产生磁场 什么叫短路?造成短路的主要原因有哪些?怎样 represent sb造句 The best way to start a person's breathing at once is to use the______method填mouth-to-mouth还是mouth to mouth "中华老字号"用英语怎么说啊 it's best not to do it all at once.[[[[all? 老字号有什么 愤怒的小鸟一共有几只? 用injure造句! "injure"用英语造句