1. [多选题]BGP is an inter-autonomous system routing protocol; it is designed to be used between multiple autonomous ( ) . BGP assumes that routing within an autonomous system is done by an intra-autonomous system routing protocol.BGP does not make any assumptions about intra-autonomous system （ ） protocols employed by the various autonomous systems. Specifically， BGP does not require all autonomous systems to run the same intra-autonomous system routing protocol. BGP is a real inter-autonomous system routing protocol. It imposes no constraints on the underlying Internet topology. The information exchanged via BGP is sufficient to construct a graph of autonomous systems connectivity from which routing loops may be pruned and some routing ( ) decisions at the autonomous system level may be enforced. The key feature of the protocol is the notion of Path Attributes. This feature provides BGP with flexibility and expandability. Path （ ） are partitioned into well-known and optional. The provision for optional attributes allows experimentation that may involve a group of BGP （ ） without affecting the rest of the Internet. New optional attributes can be added to the protocol in much the same fashion as new options are added to the Telnet protocol， for instance.
A. routers
B. systems
C. computers
D. sources
2. [单选题]某项目由并行的3个模块A． B和C组成，其中活动A需要3人5天时间完成。活动B需要6人7天时间完成。活动C需要4人2天时间完成，为了保证项目在最短时间内完成。假设活动A、B和C按时完成的概率分别为80%、70%和100%，则该项目按时完成的概率为( )
A. 50%
B. 56%
C. 64%
D. 90%
3. [单选题]如果人体缺碘，就会发生甲状腺肿大，俗称“大脖子病(endemic hypothyroidism)”。过去我国缺碘人口达7亿多，从1994年起我国实行食盐加碘政策。推行加碘盐十多年后，大脖子病(endemic hypothyroidism)的发病率直线下降，但在部分地区(some areas)，甲亢、甲状腺炎等甲状腺疾病却明显增多。有人认为，食盐加碘是导致国内部分地区(some areas)甲状腺疾病增多的原因。如果以下陈述为真，哪一项能给上述观点以最强的支持?
A. 我国沿海地区(coastal region of china)居民常吃海鱼、海带、紫菜等，这些海产品含有丰富的碘。
B. 甲亢、甲状腺炎等甲状腺疾病患者应该禁食海产品、含碘药物和加碘食盐。
C. 目前，我国在绝大多数高碘地区已经停止供应加碘食盐。
D. 某项调查表明，食盐加碘8年的乡镇与未加碘乡镇相比，其年均甲亢发病率明显增高。
