民用航空电信人员执照由()统一颁发和管理。
A、地区管理局
B、空管局
C、民航局
D、地区空管局
参考答案:C
— I'm sorry. I _____ at you the other day.
— Forget it. I was a bit out of control myself. [ ]
A. shouldn't shout
B. shouldn't have shouted
C. mustn't shout
D. mustn't have shouted
为便于储存容器的安装和维修,减小灭火剂施放时的冲击力,应在容器阀和单向阀之间采用不锈钢管连接。