整体服务数字网络
参考答案：
是一种具有可以转换及传送讯号能力的点对点公众数字通讯网络，并且通过标准通讯界面来提供广泛的综合通讯服务。
Tom as well as his friends ____ to visit our school soon after they arrive in Changsha.
A．is coming
B．are coming
C．will have come
D．has come
Terex3311E汽车多路驻车辅助电磁阀的作用？
