吡嗪酰胺：
A．视神经炎B．肝脏损害C．二者均有D．二者均无
参考答案：B
已知函数f（x）=a·2x+b·3x，其中常数a，b满足ab≠0。
（1）若ab＞0，判断函数f（x）的单调性；
（2）若ab＜0，求f（x+1）＞f（x）时x取值范围。
Which driver was to blame?
—Why,_________ !It was the child’s fault, clear and simple. He suddenly came out between two parked cars.
A．both
B．each
C．either
D．neither
