When I asked her for help,she agreed to help me________without any hesitation (犹豫). A.immediate B.immedi
已知函数f(x)=aln(x+1)﹣ax﹣x2. (Ⅰ)若x=1为函数f(x)的极值点,求a的值; (Ⅱ)讨论f(x)在定义域上的单调性; (Ⅲ)证明:对任意正整数n
―You ought to have given them some advice.―_______, but who cared what I said? A.So I did B.So ought I C.So I ought
—Many people play with mobile phones all day instead of reading books. —That’s too bad. Everyone _______ be a book lover. Reading is more enjoyable. A. may B.
对可逆反应4NH3(g)+5O2(g) 4NO(g)+6H2O(g),下列叙述正确的是( ) A.达到化学平衡时4v正(O2)=5v逆(NO) B.若单位时间内生成x mol NO的同时,消耗x mol NH3,则反
有一金属电阻丝的阻值约为20,现用以下实验器材测量其电阻率:A.电压表 (量程0~15V,内阻约为15) B.电压表 (量程0~3V,内阻约为3)C.电流表 (量
已知圆锥的母线长为5cm,侧面积为15πcm2,则此圆锥的体积为cm3.
六硅酸镁可表示为aMgO·6SiO2·H2O。确定六硅酸镁组成的方法是:取10.6g六硅酸镁,充分加热失水后,得到固体8.8g;另取相同质量的六硅酸镁加入足量盐