中版海图，我国沿海系统测量区域采用（）为深度基准。
A．理论最低潮面
B．天文最低潮面
C．平均大潮低潮面
D．平均低低潮面
参考答案：A
So engrossed in his efforts would Gaugin become that he barely noticed the passing of time.
A．delighted in
B．frustrated by
C．expanded by
D．involved in
网桥(Bridge)是______的互连设备。
A．物理层
B．数据链路层
C．网络层
D．传输层
