奇特的植物

已知两支股票的期望回报率和标准差,怎么求它们的投资组合的期望回报率呢? 喷的两个读音,当得两个读音 这两个,还有什么读音 C的两个音标读音是什么? --what do you think of this dress?--It is beautiful and it f_____me well.I like it very much(1)--what do you think of this dress?--It is beautiful and it f_____me well.I like it very much(2)Your mother seemsto be angry today______ _____ _____ your mo 已知关于X的二次三项式x^2+mx+n有一个因式(x+5),且m+n=17,试求m,n的值分解因式（x^2+5x+3）(x^2+5x-23)+k=(x^2+5x-10)^2后,求k的值设多项式A=(a^2+1)(b^2+1)-4ab(1).试将多项式写成两个非负数的和的形式(2).令A=0 LED整灯的功率因素与LED灯珠的关系是什么呢? led灯珠功率为1w光通量为5lm 当摇篮中的当字读音 读音这么读 关于+电荷释放电势能,一电子吸收电势能+电荷释放电势能,一电子吸收电势能.电势能是能量,那会不会有一天+电荷的能量枯竭,-电荷能量饱满会怎么样啊? 绕核运动的电子拥有电势能还是电磁能? 带电粒子从低地势能到高地势能电子做负功?这句话对吗 Sheryfa Luna怎么读如题 氢原子电子电势能的问题当氢原子电子在环绕原子核作半径为r的匀速圆周运动时,ke^2/r^2=mv^2/r那么电子的动能为ke^2/2r辅导书上的结论说氢原子电子的电势能的绝对值是动能的两倍也就是ke^2/r Luna用英语怎么读,含义是什么 I like c____ stamps very much 地球是不是属于太阳系 is the young woman by the window ____ English teacher ,Miss Green?A:a B:an C:also D:the The （young） lady is our English teacher对括号部分提问 this is my aunt.( )is very nice and we all like( )Your are so busy.What do you want me ( )for you?3 *( )card is this?---It's Amy's 4*How many ( )do you want?--Two kilos,please.5*Tom,you look great in your white T-shirt.填上恰当的单词,并说出 已知关于x的二次三项式x²+mx+n有一个因式（x+5),且m+n=7,求m,n的值? This moon cake is very nice.Would you like （ ）one.A.other B.another C.the other.哪个?为啥? I'm John.This is my classroom.It's old but very nice.The wall is white.The windows are green.Look ,there are twenty desks and twenty chairs in my classroom.Eleven pictures are on the wall.There are sixteen books on our teacher's desk.And twelve flowe 平均加速度和加速度有什么区别 平均加速度和瞬时加速度和加速度有什么区别啊?联系呢?详细!谢了急!在线等！！！！ 促音如何正确发音 英语单选Because our parents are growing older and older,we should visit them more whenever______.A your are convenientB it is convenientC convenient your areD convenient it is 急后面还有一句：job.We need them.And we should t＿t急后面还有一句：job.We need them.And we should t＿them for working well. 这首什么英文歌?前面听到的是 l need them什么的.很多次重复的 l need them还是l need then. 汉译英：My mom says I __ __ __,because we've __ __room to store them.我妈妈说我必须停止收藏,应为我们已经没有地方盛它们了. 为什么电子在稳定轨道上运动的能量E中,静电吸引的势能是负的?