以下选项中不属于管道荷载的类别的是( )。
A．垂直荷载 B．沿管道轴向水平荷载C．与管道轴向交叉的侧向水平荷载 D．沿管道轴向垂直荷载
参考答案：D
A．两灯可能并联
B．两灯的电阻可能相等
C．两灯可能串联
D．通过两灯的电流一定相等
He went to town _____sell one of his paintings.
A．on purpose
B．on purpose to
C．for the purpose of
D．on purpose of
