急性苯中毒主要损害
A．造血系统B．呼吸系统C．心血管系统D．消化系统E．神经系统
参考答案：E
已知a是实数，函数f（x）=x2（x-a）
（1）若f′（1）=3，求a的值及曲线y=f（x）在点（1，f（1））处的切线方程；
（2）a＞0，求f（x）的单调增区间．
Which of the following statements concerning the persistence of pricing anomalies is least likely to be correct（）
A. A lack of liquidity may cause transactions costs to exceed the profit potential of the anomaly.
B. Trading restrictions may preclude the establishment of the positions required to exploit an anomaly.
C. The capital required to exploit an anomaly is often not available.
