生活中的化学问题

在一个长度为n的顺序表中删除第i个元素时,需向前移动多少个元素. 为什么雷雨天时天空中会发生闪电 http://hi.baidu.com/%F3%DE%E4%FA/album/item/a45f755449281d52564e003a.html我只是想知道是不是他错了,我算第一个式子是mgsin0,可他是cos的！ 一辆速度为4m/s的自行车,在水平公路上匀减速地滑行40m后停止.如果自行车和人的总质量为100kg,自行车受到的阻力有多大?我算的受到的阻力是10N,重新计算后发现如果是10N就应该在80M处停止,.LX （07四川）如图所示,长方形abcd长ad＝0.6 m,宽ab＝0.3 m,O、e分别是ad、bc的中点,以ad为直径的半圆内有垂直纸面向里的匀强磁场（边界上无磁场）,磁感应强度B＝0.25 T.一群不计重力、质量m＝3×10-7 书架上有两层书,上层册数的五分之二等于下层册数的三分之一,已知下层有书132册,上层有书多少册 左边口右边幼是什么字 请问左边一个“黑”字,右边一个“今”字拼音是怎样的? 在给定的数据文件基础上,完成操作,将编写的程序代码复制到建立的word文件中,标清题号.1.假设低于1500元（含）免税；1500（不含）元到3000元（含）税率为5%；3000（不含）元到5000元（含）税 书架上有上下两层书,上层比下层多30本,下层比上层少5分之2,书架上有书多少本? 当代3位最有名的数学家中国外国都可以, 灭火器怎么用啊!急!帮帮我 电脑上就能做的,急 please give _____ book A.she her B.his his C.me my D.they themplease give _____ book A.she her B.hiplease give _____ book A.she her B.his his C.me my D.they themplease give _____ book A.she her B.his his C.me my D.they them Please give the book to (i)（选择适当的形式填空) What I love so much about life is that it's a mystery and who knows what lies 为什么微积分的解∫[1,2](x^2-2x-3)/x第一步是（x^2-2x-3）/x = x - 2 - 3/x(1,2) (x^2-2x-3)/x dx=∫(1,2) (x^2-2x-3)/x dx ⑴=∫(1,2) x-2-3/x dx ⑵=x^2/2-2x-3lnx |(1,2)=(2-4-3ln2)-(1/2-2)=1/2-3ln2 第一步是怎么变成第二步的? 解不定积分1/x*(2x^4+2x^2+1)^1/2 流转税简单解释 1. Laura Ingalls Wilder wrote many books about her life in the wilderness. Unit 1 is a true story from one of her books. On the edge of the Big Woods of Wisconsin in 1872, she lived with her family in a little log house. It is miles from any neighbor 英语语法题 About 40percent of the population of the country __________on farms.A.live b .stays cAbout 40percent of the population of the country __________on farms.A.live b .stays c.lives d.is理由 despite much research,there _____still certain elements in the life cycle of the insectthat ____not fully understood. A is,is B is,are C,are,is Dare,are Please give she a pencil-case修改病句 二次积分和三次积分的几何意义一样吗?几何意义各是什么? But forms of address reveal many assumptions we make about members of our speech community We must address the root cause behind much of the instability in our markets这句话 关键是当中 怎么翻 root cause 英语翻译Our company forms part of a consortium of local businesses working for environmental change. 化二重积分f(x,y)为二次积分D是由y轴,y=1及y=x围成的区域.f(x,y)dxdy=dx从o到1的积分乘以f(x,y)dy0到lnx的积分（双重积分和积分符号打不出来,请见谅）其中乘号后面一个积分的范围为什么是0到lnx阿? 求二次积分 ∫∫(x^2+y^2)dσ的二次积分为 m是什么实数时,关于x的一元二次方程mx^2-(1-m)x+m=0没有实数根.已知函数f(x)=1/2x^2-3x-3/4,求使函数值大于0的取值范围 lives/the/forest/in/at 连词成句