已知△ABC的重心为P，若实数λ满足：+=λ，则λ的值为A.2 B. C.3 D.
《旧唐书》称：武则天“制公卿之死命，擅王者之威力”（意为诛杀公卿，独断专权）。武则天遗言无字碑，由后人评价自己的功过。史学家之所以肯
如下性质的递变不正确的是( )A．HCl、H2S、PH3的稳定性依次减弱 B．HClO4、H2SO4、H3PO4、H4SiO4的酸性依次减弱(相同条件下)C．CsOH、KOH、LiOH的碱性依次减
He told us whether________a picnic was still under discussion. A．to have B．having C．have
在平面内，相交的两条直线是中心对称图形，它的对称中心是
已知H2O2在催化剂作用下分解速率加快，其能量随反应进程的变化如图所示。下列说法正确的是( ) A．H2O2分解属于吸热反应 B．加入催化剂，减小了反应
We invited her to dinner but she didn’t even bother to _______ . A. turn in B. turn up C. turn on D. turn down
This is a great truth, one of the greatest truths. It is a great truth because once we truly see this truth, we transcend（超越） it. Once we truly know that life is difficult---once we truly unde
