参加公益活动的感想

把两个棱长为5分米的正方体,拼成一个长方体后,其表面积是原来一个正方体表面积的多少 把圆x^2+y^2+2x-4y-a^2-2=0的半径减小一个单位则正好与直线3x-4y-4=0相切,则实数a的值为 关于地球五带的分界线纬度范围和特点 巴西最北、最南的纬度是多少度?在地球的“五带”中,巴西主要属于哪一个带? 甲、乙、丙三人行走的速度依次分别为每分钟30M、40M、50M.甲、乙在A地,丙在B地,同时相向而行,丙遇乙后10分钟和甲相遇.求A、B的距离 甲乙丙三人进行60m跑 甲到终点时 乙跑了50m 丙跑了45m 乙到终点时 丙离终点还剩多少m 给410A空调抽真空一定要专用真空泵吗?给410A空调抽真空一定要专用真空泵吗,现成修冰箱用的真空泵不能用吗?如果是为了在突然停电时真空泵油进入系统,可否加装一个单向阀来解决? whose essay is the best in your class sally‘s,Her essay is better than（）A Tom’s and Lily‘s B Tom and Lily‘s选哪个?为什么? 暖手宝里水变少了?怎么办 please write out the complete forms of the wordsInternetE-mail IECD-ROM How much do you know about computer?Please write out the complete forms of the words.Internet——E-mail——BBS——IE——WWW——CD-ROM——IT—— How much do you know about the computer?Please write out the complete forms of the words.Inrenet--Email--BBS--IE--WWW--CD-ROM--IT-- 稀盐酸和三氧化二铁为什么不是生成氯化亚铁而是生成氯化铁 read the following entry from a student.thereread the following entry from a student.there are nine mistakes .underline each intcorrect word andwrite the correct one on the right；；；这是什么意思 turn the following nouns into the plural from,and then read them aloud什么意 鸦片战争、甲午战争,分别打了几年? 抗旱用水泵请高手帮我看一下每度电可以抽多少方水垂直高差有5米和8米两种情况,管道长400米,管道内径150毫米塑料管,流量在50方每小时,请教在这样条件下的现代水泵技术一度电能抽多少方 甲乙同时从A到B地,甲每分走80m乙每分走60m甲到达B地后返回与乙相遇.AB之间距700米甲乙两人行几分相遇 理论上1度电能把多少立方水抽到10米高处就算是效率为100％的高效率水泵?重力加速度取10时!希望能给出计算过程,要物理学与动力学高手才能回答吧!呵呵 Read it and write a summary（第二篇）2.Did Humans Lose Their Sixth Sense?At one time humans also had this sixth sense,Rabinowitz said,but lost the ability,when it was no longer needed or used.Joyce Poole is director of the Savanna Elephant Vocal Read it and write a summary2. Did Humans Lose Their Sixth Sense? At one time humans also had this sixth sense, Rabinowitz said, but lost the ability, when it was no longer needed or used. Joyce Poole is director of th 甲每分钟行60M,乙每分钟行65M,丙每分钟行75M如果甲乙二人在1村,丙在2村,他们三人同时由两村相向而行,丙遇到乙后,继续行走10min遇到甲,求1,2两村相距多少米 write a paragraph of about 130 words on the topic:The most important thing I think I should learn at collegeYou can follow the outline:1)The thing;2)Your reason(s);3)Your conclusionThanks! 请问在英国除了用插头转换器还用变压器么? if you go into the forests with friends有没有全文翻译、、咱要翻译! 已知关于x的二次函数f(x)=x^2+(2t-1)x+1-2t.1 对于任意t∈R,方程f(x)=1必有实数根；2 求证：f(x)=0在区间（－1,0）及（0,1／2）上各有一个实数根．2若1/2 已知关于x的二次函数f(x)=x的平方+（2t-1)x+1-2t.(1)求证：对于任意t属于R,方程f(x)=1必有实数根；(2)若1\2 把甲午战争、解放战争、鸦片战争、北伐战争按时间顺序排列 Read and complete the writing with the words in the box所给单词:discover culture supper sour suggest wheat experienceT like Chinese ( ) and I love Chinese food a lot.There's a nice Chinese restaurant near my home and I go there almost every day f 已知f(x)=x³+sinx,x∈(-2/π,2/π),解不等式f(1-x)+f(1-x²)＜0 用导数怎么解 1、把下列汉字按声母发音部位进行归类：散、曾、跑、闹、六、字、是、学、日、黄、接、起、顿、派、目、福 用当dàng,dāng组词.