题目

They produced a new record in 1996, that was a celebration of their time. 答案：that →which解析：that不能引导非限制性定语从句，要用which。当圆锥的侧面积和底面积的比值是2时，圆锥轴截面的顶角等于（　　）A．45°B．60°C．90°D．120°