胎规格的表示方法中,外径用字母()表示。
A.d
B.H
C.D
参考答案:C
The news of the Ministry's coming to our school for a visit was ____ on the radio yesterday.[ ]
A. turned out
B. found out
C. given out
D. carried out
依据《中国电信移动网络运行维护规程》事件处理的服务标准,重大通信事故和重大事件:不超过()小时。
A.1
B.2
C.4
D.8