下图表示人体细胞受到病毒攻击后发生的部分免疫反应，据图回答有关人体免疫的问题。
图中“某种初始状态的T细胞”产生的细胞分泌物是（）
参考答案：淋巴因子
《长沙晚报》曾发表过题为《网络时代，个人隐私也需“防火墙”》的文章。下列属于个人隐私“防火墙”的有
①增强法律观念，依法律己 ②增强自我保护意识，给自己的隐私上把锁
③认真选择倾诉对象④上网时要掌握网上安全运行知识
A．①②③④
B．①②③
C．②③④
D．①③④
Frame Relay is simplified form of (51) , similar in principle to (52) , in which synchronous, frames of data are routed to different destinations depending on header information. Packets are routed throught one or more Virtual Circuits known as (53) . Most Virtual Circuits are (54) , which means that the network provider sets up all DLCI connections at subscription time. (55) are also part of the Frame Relay specification. They privide a link that only lasts only as long as the session.
A．Permanent Circuits
B．Permanent Virtual Circuits
C．Switched Virtual Circuits
D．Switched Circuits
