a的复数形式

貌似很简单.可是还是不会的说、求帮助.一.用列举法表示下列集合：1.{x|x+y=7,x包含于N,y包含于N}2.{(x,y)|x+y=7,x包含于N,y包含于N｝3.{y|y=x^2-1,-2错了，第一题1 2 是N+ - - 抱歉。么看见。设集合B={X包 Finish the sentences的中文,越快越好 对于函数f（x）=x则称x为f（x）的不动点，若f（f（x））=x，则称x为f（x）的稳定点，函数f（x）的不动点和稳定点的集合分别记为A,B即A={x|f（x）=x} B={x|f（f（x））=x}（1）求证：A≤B(2)若f（x Word Games Use your brain and try to finish the foiiowing sentences1.Father is to son as mother is to duaghter.2.Foot is to shoe as hand is to ( ).3.Hat is to head as coat is to ( ).4.Pencil is to paper as chaik is to ( ).5.Cow ia to beef as pig ia t 帮翻译一句话:OTHER THAN THOSE UNDER US/UN SANCTIONS finish的完成时态 We must _______ before the exam.A go overWe must _______ before the exam.A go over B go it overC go over it D go the texts over这道题答案为什么选C,请分析一下, All these exercises must__ __(finish)before school is over.被动语态. 区分every one & everyone may be & maybe能帮我区分下么? suddenly everyone gets to know there might not already be tommorow怎样翻译 excuse me but can i be you for a whilemy dog won't bite you if you sit real stilli got the anti-christ in the kitchen yellin at me againyeah i can hear that been saved again by the garbage trucki got something to say you know but nothing comeyes i kn They like giving him candies as a treat(改为同义句)They like giving him some candies as a treat(改为同义句)They like giving them ______ ______ ______ some candies. 我问下何时改北平为北京.是不是毛泽东认为有我才有今天才改北平为北京的. 到底是谁把北平改成北京的?因为我学历史课的时候,书上讲是明朝明成祖朱棣把京城迁的北平改为北京的,但是为什么有些人说是中国解放后才改的呢?到底谁是对的? 请问一下the respirometer water 北京为什么要改成北平请回答, The water Mansions的意思 建国初期我们为什么要把北平改成北京啊? The ice one regular field 11 vs.11和one 9 vs.9 field in turf 体育方面的 The teacher will accept late work she will reduce the grade by 5%The 22.The teacher will accept late work,_______ she will reduce the grade by 5%.A.while B.so C.but D.if 为什么选C不选A,but与while的用法究竟有何区别,请就本题或者 为什么北京要改为北平?（民国时） The 22.The teacher will accept late work,_______ she will reduce the grade by 5%.A.while B.so C.but D.if 如何翻译?为什么不能选A表转折呢? You'd better not r---------her invitation to the party .She really hopes that you will come. 急、急、急!求翻译：The frogs and birds sang their boasts,hopes and threats. the sun __,the birds went into their nestsA set down B sets down Csetting Dsets 但A为什么不行呢 birds-----their wings rapidly as they fly ona hit b knock c beat d strike 英语发音 t 如何发音：ex important 和 Manhattanex ：impoTant 和 manhaTTan 这两个单词 外国人说的时候 （词中大写的）T 不发t的音 而发en 的音或者nen的音 .请问这是怎么回事啊,还有我怎么练习也还是 One’s attitude is always important.If you are lazy and weak,you will never taste any success.Bu i will ___ ____ ____ (尽最大努力）to finish the important work.填什么 The water goes up “埮（tan)”的潮汕读音为什么?