substring的用法

向量(AB+MB)+(BO-CB)+OM化简后= 向量AB+向量MB)+(向量BO+向量BC)+向量OM 怎么求 Gmat语法疑问,关于同位语.最近看到关于同位语的一个语法：“同位语结构中名词的数可以和其修饰对象的数不一样”.哪位大虾能不能给我举个例子, GMAT语法问题求解Several educational research groups are denouncing the mayor's proposal of a system by which individual teachers would be given raises or bonuses "should it be that test scores show their students' mastery of read GMAT语法问题,求高人指点. GMAT语法,逻辑谓语疑问By 1940, the pilot Jacqueline Cochran held seventeen official national and international speed records, and she earned them at a time when aviation was still so new formany of the planes she flew to be of dangerously expe GMAT语法时态问题A 1972 agreementbetween Canada and the United States （reduced the amount of phosphatesthat municipalitieshad been allowed to dump） into the Great Lakes.(A) reduced the amountof phosphates that municipalities had been allowed 在复平面内,O为坐标原点,向量oa对应的复数为-2-i,若点a关于直线y=-x的对称点为b,则向量ob对应的复数为 设向量a,b均为单位向量,且（a+b)²=1,则ab夹角为?我算出了,（a+b)²=a²+b²+2ab,但我看答案a²+b²直接成了2,就成了2+2ab=1,a²+b²=2是怎么知道的 名人正确认识自己的事例 (向量AB+向量MB)+向量BO+向量OM 怎么算啊?拜托各位大神 GMAT的语法题New theories propose that catastrophic impacts ofasteroids and comets may have caused reversals inthe Earth’s magnetic field,the onset of ice ages,splitting apart continents 80 million years ago,andgreat volcanic eruptions.􀂃 一道GMAT 语法题Beatrix Potter,in her book illustrations,carefully coordinating them with her narratives[/u],capitalized on her keen observation and love of the natural world.(A) Beatrix Potter,in her book illustrations,care-fully coordinating th Gmat 语法题求答案71. Unlike the original National Museum of Science andTechnology in Italy, where the models are encased inglass or operated only by staff members, the VirtualLeonardo Project, an online version of the museum,encourages visitors 一道GMAT语法题~By applying optimization techniques commonly used to plan operations,it is possible to determine how much effort ought to be devoted to each of a company’s products in order to meet its goals in both the short and long terms.\x0 向量a²= |a|² 是否正确 电路中感应电动势的大小,是由穿过这一点路的----所决定的.a 磁通量 b 磁通量的变化量 c 磁通量的变化率以上填空的三个选项,正确的显然是c,但你能说明选项a和选项b的含义吗?你认为当年安 陆游的生平简介越简介越好,最好只有一句话! 证明过定圆M上的定点A作圆的动弦AB,若2向量MP=向量MA+向量MB,则动点P的轨迹方程为 课题是青海高原一株柳,作者为什么这段话中用了许多笔墨去写家乡灞河边的柳? 在平面直角坐标系中,已知A(0,-1)B点在直线Y=-3上,M点满足MB向量平行OB向量,MA向量乘以AB向量=MB向量...在平面直角坐标系中,已知A(0,-1)B点在直线Y=-3上,M点满足MB向量平行OB向量,MA向量乘以AB向量=MB 求解已知MA向量＝(－2,4),MB向量＝(2,6),则1／2AB向量等于多少? 若|a+b|=|a-b|,则a*b=0（向量)是不是真命题,为什么 已知向量a=（2,1+sinθ）,b=（1,cosθ）,命题p：“存在θ∈R,使a⊥b”,试证明命题p是假命题. 若|向量a|=0,则向量a=0 这个命题对吗 为什么命题“向量a*b=0,则向量a垂直于b"为假命题?虽然ab均有可能为0向量,但0向量垂直于任何向量（包括零向量）啊?是不是要考虑空间向量呢?楼上说得对，是ab不是*乘，打差了，还有0垂直于0 三个力分别是6 8 12N,求合力范围 求三个力合力范围?如3 4 5N这三个力 如何求3个力的合力的范围 如果a²>b²,那么a>b,是真命题吗?如果是请证明. p是三角形ABC内一点.AP=二分之一AB加三分之一AC 是向量 则三角形PBC,和三角p是三角形ABC内一点.AP=二分之一AB加三分之一AC 是向量 则三角形PBC,和三角形ABC的面积比是多少? 向量的模的计算已知A（4,1）,b（7,5）,C（-4,7）求|AB|,|AC|,能具体点吗?最好告诉我这是用了一个什么公式,好方便我举一反三,做类似的题