集线器(HUB)设备用来连接()
A、两个采用不同协议的LANs
B、一个LAN和一个WAN
C、一个LAN和一个MAN(城域网)
D、一个LAN中的两个网段
参考答案:D
He ______ the army the year before last. [ ]
A. joined in
B. joined
C. attended
D. took part in
调节系统的扰动试验主要包括哪几种?