火灾出处于（）阶段，是扑救得最佳时期。
A.初起
B.发展
C.猛烈
D.下降
参考答案：A
Advertising is different from other forms of communication in that the advertiser pays for the message _____. [ ]
A. to deliver
B. delivered
C. to be delivered
D. delivering
HTTP会话过程包括( )几个步骤。
A．连接、应答、关闭
B．请求、连接、应答、关闭
C．连接、请求、应答、关闭
D．请求、认证、应答、关闭
