题目

 —What’s the matter?    —They said I should not be allowed    here. They don’t allow __in the waiting room. A. smoking, to smoke           B. to smoke, smoke    C. to smoke, smoking           D. smoking, smoking 答案：C已知关于的一元二次方程的一个根为0,则的值为(    ) A．1B．1和－3C．－3D．不等于1的任何数