i平方的前n项和怎么算

为什么我的数学成绩不会提高?怎么补?我已经很努力了 I hope you be just as before to me good这话是什么意思I hope you be just as before to me good这句话是什么意思,麻烦给翻译下!谢谢 It is not polite to ask----(person) questions.横线上应填什么 英汉互译 ：feel warm or cool （ ） 你今天感觉怎么样?( ) 她妈妈很难过（ ） 他觉得高兴吗?（ ）还有一个 汤姆的弟弟不在家（ ） Do you feel warm?肯定回答和否定回答 首字母填空 1、It's not polite (礼貌的) to ask a woman about her (a ）.2、Our English tescher usually (s )his class with an English song.3、I'm (g )to konw that you are well now.4、He'd like to read sonething about for (f ). 请问我该怎样提高数学呢?一直努力都不见有效果. 在关于数学方面的努力提升应怎么表达? 翻译:It is the closest to success when you feel the most pained It's impolite to ask （person）question Ask each other question Thank you! "Ask each other question"的中文意思是：回答另外一个问题? I like listening to music 同义句转换I( ) ( ) to music 海峡两岸的作文 I find English very hard. 如图,在角ABC中,AB=AC,DB=DC,DE⊥AB,DF⊥AC,垂足为E,F,求证：DE=DF.这个是图 海峡两岸的关系论文 Look!Jiamin play football with his classmateplay换个词There ____some books and a clock on the desk The clock___three hands.A.are,is B is,has C.are,has D.for the supper 英语用被动语态写一篇50词的短文.My day. 英语美文 并且带读后感我需要短篇美文,并带读后感的、读后感是英文哦~ 海峡两岸传承文化有哪些 翩翩起舞造句教教我吧! I find it is too hard的同义句它的同义句是什么要改成 I find it — — .后面是两个空 用栖息.聆听.翩翩起舞造句 I find it very hard ____maths.A learn good B to learn good C learn well D to learn well 心旷神怡和翩翩起舞造句（50~60字）除了：风,那么轻柔,带动着小树、小草一起翩翩起舞,当一阵清风飘来,如同母亲的手轻轻抚摸自己的脸庞,我喜欢那种感觉,带有丝丝凉意,让人心旷神怡.享受 i found it hard to be understood.为什么不能这样说?不是存在被动的关系么 让心情翩翩起舞.这样造句可以吗? I found it hard to understood为什么不是I found it is hard to understood 海峡两岸同根情征文 急 补全英语对话片段2.Situational Dialogues 五个场景：1.Traveling by rail 2.In the library 3.At a birthday party 4.Showing around a factory 5.To comfort your best friend when he/she is in trouble 要求：① 每两人自由组合成一组 翩翩起舞造句