六氟化硫气瓶不得与其他()混放。
A.设备
B.仪器
C.工具
D.气瓶
参考答案:D
The reporters exposed the corruption (腐败) of several high officials in the government;
as a result, they ________ to resign from office.
A.asked
B.were asked
C.had been asked
D.have asked
OSPF协议使用( )分组来保持与其邻居的连接。