____ ____ the book called Oliver Twist, I think it is really fantastic.
已知O为坐标原点,双曲线x2a2-y2b2=1(a>0,b>0)的右焦点F,以OF为直径作圆交双曲线的渐近线于异于原点O的两点A、B,若(AD→+AF→)•OF→=0,则双曲线的离心率e为( )
一慢性贫血患者突患急性阑尾炎,到医院做血常规化验,其化验结果可能在正常值外的是( )
当x满足不等式x-1≥1(1)2x-x-1≤5(2)时,求方程x2+2x-8=0的解.