大区制移动通信系统优点。
参考答案：
具有网络结构简单无需无线交换直接与PSTN相连，投资少，见效快。
-________ the weather report, there's a heavy rain this evening.
-Thank you.I'll bring an umbrella.[ ]
A．According to
B．According as
C．Due to
D．Because of
超长结构混凝土浇筑应符合哪些规定？
