in+a+burst+of+speed

臧采怜5219非谓语动词 名词+介词短语A robber burst into the room, knife in hand.后半句.a knife in his hand可以么?还是前面必须加with才能这样用?谢谢! -
甘栏该13554081182 ______[答案] A robber burst into the room with knife in hand. with + a knife in his hand 作伴随状语. 我是从事英语的,不明再问.

臧采怜5219give+a+thought+to是什么意思 -
甘栏该13554081182 ______ give a thought to 译为....给想...1.In those cases, you translate the verb or noun and don't give a thought to the preposition in the source language: just use the preposition required in the target language. 在这种情况下,你翻译动词或者名词,不要考...

臧采怜5219已知cos(a+b)=0,求证:tan(2a+b)+tanb=o -
甘栏该13554081182 ______ cos(a+b)=0 sin(a+b)=1 tan(2a+b)+tanb=tan[a+(a+b)]+tanb=[sinacos(a+b)+cosasin(a+b)]/[cosacos(a+b)-sinasin(a+b)]+tanb=-cosa/sina+tanb=(sinbsina-cosacosb)/sinacosb=-cos(a+b)/sinacosb=0

臧采怜5219A、B、C、O血型中的A+、A - 、B+、B - ……是什么意思? -
甘栏该13554081182 ______ A、B、O型中的阴性或阳性.加号为阳性,减号为阴性.这里阳性和阴性只是区分血的类型,不是说阳性有问题.献血证标注血型都给写A+、A—、B+、B-、O+、O-

臧采怜5219安全炸药三硝酸甘油酯(C3H5O9)发生爆炸的反应方程式为4C3H5N3O9 引爆剂 . 12CO2↑+10H2O↑+6X↑+O2↑其中X的化学式为( ) -
甘栏该13554081182 ______[选项] A. N2 B. NO C. N2O D. NO2

臧采怜5219已知 Δy=AΔx+o(Δx),为什么就有Δy/Δx=A+o(1)? -
甘栏该13554081182 ______ β=o(Δx)表示Δx的高阶无穷小,即lim[β/Δx]=0 所以lim〖∆y/∆x〗=lim (A∆X+o(Δx))/∆X=A+0 当然因为o(1)=0,所以也是成立的.

臧采怜5219已知cos(π/2+α)=2sin(α - π/2),求[sin^3(π+α)+cos(α+π)]/[5cos(5π/2 - α)+3sin(7π/2 - α)]= -
甘栏该13554081182 ______[答案] cos(π/2+α)=2sin(α-π/2) 即:-sinα=-2cosα 得:tanα=2 原式=(-sinα-cosα)/(5sinα+3cosα) 分子分母同除cosα =(-tanα-1)/(5tanα+3) 把tanα=2代入 =(-2-1)/(10+3) =-3/13 祝你开心!希望能帮到你,如果不懂,请追问,祝学习进步!O(∩_∩)O

臧采怜5219在如图所示的△ABC中,内角A,B,C所对的边的长分别为a,b,c,已知a=c,且满足cosC+(cosA - 3sinA)cosB=0,若点O是△ABC外一点,且OA=2OB=4,∠AOB... -
甘栏该13554081182 ______[选项] A. 4+4 3 B. 5+4 3 C. 12 D. 8+5 3

臧采怜5219小学语法知识 比如 be+动词ing等 -
甘栏该13554081182 ______[答案] 【小学英语语法知识点汇总】 1.人称代词 主格:I we you she he it they 宾格:me us you her him it them 形容词性物主代词:... 不规则变化:well-better,much/many-more,etc.3.可数词的复数形式 Most nouns + s a book –books Nouns ending in a ...

臧采怜5219如果令ABCDEFGHIJKLMNOPQRSTUVWXYZ分别对等于1—26等数字,M+O+N+E+Y=13+15+14+5+25=72R+E+S+P+O+N+S+I+B+I+L+I+T+Y=? I+N+T+E+L... -
甘栏该13554081182 ______[答案] 按规律,M是13,N是14,O是15,那么可以推断A为1,B为2.,依此类推,把数字代进去,每个式子的答案就出来了