以下选项中,属于广域网的是________。
A.宿舍网
B.国家网
C.校园网
D.楼宇网
参考答案:B
Some parts in south China have experienced _____ this year as they did last year.
A.twice as much rain
B.rain twice as much
C.as twice much rain
D.twice rain as much
简述人员密集场所发生火灾时的扑救对策?