To their great relief, the missing child returned home, ______, after an absence of two weeks.

A．looked tired and healthy

B．tired and healthy

C．tiredly and healthily

D．looking tired and healthily

网络管理的主要目标是( )。

A．减少停机时间，改进响应时间，提高设备利用率

B．减少运行费用，提高效率

C．减少或消除网络瓶颈

D．以上都是