业务网使用的VC-12通道，其运行指标中的降质限值（）。A.4个ES B.3个ES

前列腺增生症最早的症状是()

A．排尿困难

B．排尿时间延长

C．夜尿次数增加

D．排尿不尽

E．残余尿增加

下列反应的离子方程式书写正确的是（　　）

A．碳酸钡溶液中加入稀硫酸：BaCO₃+2H⁺=Ba²⁺+CO₂↑+H₂O

B．氢氧化钠溶液中通入少量二氧化碳：CO₂+2OH^-=CO₃^2-+H₂O

C．氯化铜溶液中加入过量NaOH：Cu²⁺+2NaOH=Cu（OH）₂↓+2Na⁺

D．苛性钠溶液中加入稀醋酸：H⁺+OH^-=H₂O

苯环上含有下列哪一个基团时磺化速率最慢（）

A.-Br

B.-COOH

C.-COCH3

D.–NO2

2008年10月8日，华康实业发展有限责任公司与上岛对外贸易服务公司签订废钢轨购销协议，合同价款为320万元。根据合同，上岛对外贸易服务公司向华康实业发展有限责任公司交付一张320万元的银行承兑汇票，付款人为中国工商银行天津市分行(以下简称银行)，11月1日华康实业发展有限责任公司提示承兑，银行经办人以为出票人在银行有足额存款，即在承兑人栏中盖章承兑，之后，发现出票人在银行无存款，银行即以重大误解为由，书面通知华康实业发展有限责任公司撤销承兑。华康实业发展有限责任公司未予理会，于12月6日将汇票背书转让给海地装修有限公司还其装修款。12月23日海地装修有限公司因还材料款而将此汇票转让给中良装饰有限公司，但在背书时，背书人栏内签署了经办人张某姓名，未盖单位公章。此案中，下列哪些当事人应承担票据责任( )

A．上岛对外贸易服务公司

B．华康实业发展有限责任公司

C．中国工商银行天津市分行

D．海地装修有限公司及其经办人张某

In the following passage, there are 20 blanks representing the words that are missing from the context. You are to put back in each of the blanks the missing word． The time for this section is 20 minutes.
Where do you really come from And how did you get (1) where you live today DNA studies suggest that all humans today (2) from a group of African ancestors who—about 60,000 years ago— (3) a remarkable journey.
The Genographic Project is seeking to chart new (4) about the migratory history of the human species by (5) sophisticated laboratory and computer analysis of DNA contributed by hundreds of (6) of people from around the world． In this unprecedented and real-time (7) effort, the Genographic Project is closing the gaps of what science (8) today about mankind’s ancient migration stories.
The Genographic Project is a five-year (9) partnership led by National Geographic Explorer-in-Residence Dr. Spencer Wells. Dr. (10) and a team of renowned international scientists and IBM researchers, are (11) cutting-edge genetic and computational technologies to analyze historical patterns in DNA (12) participants around the world to better understand our human genetic roots. (13) three components of the project are: to gather field research data (14) collaboration with indigenous and traditional peoples around the world; to invite (15) general public to join the project by purchasing a Genographic Project Public Participation Kit; (16) to use proceeds from Genographic Public Participation Kit sales to further (17) research and the Genographic Legacy Fund which in (18) supports indigenous conservation and revitalization projects. The Project is anonymous, non-medical, (19) , non-profit and non-commercial and all results will be placed in the (20) domain following scientific peer publication.