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问题 选择题

下列疾病中，通过预防接种能预防的是（　　）

A．色盲

B．白化病

C．冠心病

D．甲型H1N1流感

答案

A、B色盲、白化病是由于人体内遗传基因的改变而引起的疾病，属于遗传病．故不符合题意．

C、“冠心病”是冠状动脉硬化性心脏病的简称．不是传染病，故不符合题意．

D、甲型HINl流感是有甲型HINl流感病毒引起的一种传染病，可通过注射甲型HINl流感疫苗来预防，属于传染病，故符合题意．

故选：D

选择题

位于欧洲、非洲、南极洲和南、北美洲之间的大洋是（　　）

A．太平洋

B．印度洋

C．大西洋

D．北冰洋
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单项选择题 共用题干题

Astute service providers realize that the continued support of legacy X.25 and asynchronous network element using separate operations network is cost(16).For example,the maintenance of multiple networks can require additional staff. Often, this staff must be trained on multiple vendor technologies, sometimes requiring parallel groups specializing in each (17) .Hence, additional maintenance procedures must be maintained and administrative records are (18) .The duplication of transport facilities to carry (19)network traffic is an inefficient use of resources. And not surprisingly, more technologies installed in a central office means the necessity for more physical space, and an increase in power connections and power consumption migration of these (20) network elements to IP-based DCns is alogical strategy.

空白处（17）应选择（）

A.line

B.platform

C.sever

D.switch
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