悬吊式锅炉的水封槽应有足够的水源，并在内侧面产生一定量的水膜。
参考答案：对
It has been proved _______ violence on television has a bad effect on children.
A．whether
B．because
C．what
D．that
以数据透视表形式组织的数据访问页称为______。
