______的主要目的是将一条原始的、有差错的物理线路变为对网络层无差错的数据链路。

题型:填空题

问题:

______的主要目的是将一条原始的、有差错的物理线路变为对网络层无差错的数据链路。

考点:计算机等级考试网络技术三级网络技术笔试
题型:填空题

为保证用户电压稳定在220V,变电所需适时进行调压,图甲为调压变压器示意图.保持输入电压u1不变,当滑动接头P上下移动时可改变输出电压.某次检测得到用户电压u2随时间t变化的曲线如图乙所示.以下正确的是(  )

A.u2=190

2
sin(50πt)V

B.u2=190

2
sin(100πt)V

C.为使用户电压稳定在220V,应将P适当下移

D.为使用户电压稳定在220V,应将P适当上移

题型:填空题

Welcome to catch the excitement of your child on film while fishing and enter his or her picture in the yearly contest! The contest is sponsored by Virginia Department of Game and Inland Fisheries(VDGIF)in celebration of National Fishing Week!

The winning pictures are those that best catch the theme “kids enjoy fishing”. Winners will receive different fishing-related prizes. Winning pictures will also be posted on the VDGIF website and may be used in all kinds of VDGIF publications. There is no need to be a professional photographer. Any photo will do.

Contest Rules

·Children in the photos must fall into one of the following age groups when the picture is taken: 1—5,6—10.

·Photos must not be more than 1 year old.

·Photos must be taken in Virginia.

·Children in a boat must be wearing a life jacket.

·Only one photo submission per child.

·Submit photo on photograph quality paper, no CD’s accepted.

·Photos must not be bigger than “4×6” size.

·Please stick a piece of paper to the back of the photo including: name, age, address, phone number and location where the photograph was taken.

·Photos must be postmarked on or before June 19, 2011.

·Judging will take place in July and winners will be posted on the VDGIF website.

·Prizes will be sent directly to the winning children.

·This contest isn’t open to immediate family of VDGIF employees and sponsors. Immediate family members refer to children, relatives or others living in the same household with a VDGIF employee or sponsor.

To Enter:

Send your photo, with the child’s name, age, phone number and address to: 2011 Kids’n Fishing Photo Contest…

小题1:The purpose of the contest is to          .

A.encourage people to take more pictures

B.celebrate a national fishing-related activity

C.help people realize the importance of fishing

D.encourage people to go fishing with kids小题2:Which of the following photos can enter the contest?

A.A photo which was taken in California in 2009.

B.A large photo whose postmark is July 11, 2011.

C.A photo which was taken in Virginia on September 23,2010.

D.A photo on which there is a 12-year-old girl.小题3:What can be known about the prize of the contest?

A.Winners will get a great deal of money.

B.Winners will be allowed to travel in Virginia for free.

C.Winners’ works will be seen on any website.

D.Winner’s works may appear on the covers of VDGIF publications.

题型:填空题

某国有企业拟改制为公司。除5个法人股东作为发起人外,拟将企业的190名员工都作为改制后公司的股东,上述法人股东和自然人股东作为公司设立后的全部股东。根据我国公司法的规定,该企业的公司制改革应当选择下列哪种方式( )

A.可将企业改制为有限责任公司,由上述法人股东和自然人股东出资并拥有股份

B.可将企业改制为股份有限公司,由上述法人股东和自然人股东以发起方式设立

C.企业员工不能持有公司股份,该企业如果进行公司制改革,应当通过向社会公开募集股份的方式进行

D.经批准可以突破有限责任公司对股东人数的限制,公司形式仍然可为有限责任公司

题型:填空题

启动大泵向井内注前隔离液前,必须进一步核实排水闸门处于打开状态,如倒错闸门会有什么危险?

题型:填空题

关于地球外部圈层的叙述,正确的是()

A.地球的外部圈层包括岩石圈、水圈、生物圈、大气圈

B.生物圈是地球表层生物及其生存环境的总称,包括大气圈、水圈和岩石圈

C.人类生活的地球表层是开放的、均一的系统

D.生物圈是大气圈、水圈和岩石圈相互渗透、相互影响的结果

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