问题 阅读理解
Today’s teens have a knowledge of the Internet that often surpasses(超过) that of their parents. Because so many teens are Internet savvy(了解, 常识), it is important that they also have an understanding of the dangers that exist online and how to deal with them. Watch teens share their own “Real-Life Stories” about issues affecting them on the Internet such as cyberbullying (网络欺凌), online enticement(诱惑), and giving out too much personal information.


NSTeens - Terrible text
Some teens say and do terrible things to each other online because they don’t see the direct effects of their actions. So what should you do if you're cyberbullied? Watch the NSTeens in their latest video, "Terrible text," about a young girl who is troubled when a cyberbully sends mean text messages to her cell phone at all hours of the day and night. Visit NSTeens.org.
NetSmartz411
NetSmartz411 is a parent and guardian’s premier, online resource for learning about Internet safety, computers, and the Web.
Search our knowledge base for answers to all of your questions about the online world! If you can’t find what you’re looking for, use the “Ask the Experts tab ”to send us a question.
Your question will be answered by professionals who know a lot about Internet safety —— the real-life analysts at the National Center for Missing & Exploited Children. We handle daily reports about the online exploitation of children; and well show you the steps you can take to keep the children and teens in your life safer online.
Visit NetSmartz411.org.
CyberTipline Report
The CyberTipline is the place to report any incidents of Internet exploitation. If you find yourself in a situation where you need help, visit cybertipline.com and make a report. If you fear that you are in immediate danger, contact your local law enforcement (执法部门).
Real-Life Stories
Watch real-life stories told by teens who have been victims of Internet exploitation.
Real-Life Stories
NetSmartzKids
Are you concerned about your younger brothers or sisters safety online? Visit  NetSmartzKids.org with them to help them learn how to avoid the dangers that exist on the Internet.
 
55. The ad is intended for _______.
A. kids loving to play games online
B. only victims of Internet use
C. kids and their parents who want to learn about the safety online
D. pre-school students who know little about Internet
56. If you visit the website, you can ________.
A. share your friends “Real-life Stories” about issues affecting them on the Internet
B. have an understanding of the dangers that exist online and how to deal with them
C. say and do terrible things to each other online
D. ask for help when you have difficulty with your study
57. If you visit cybertipline.com, you can _______.
A. contact your local law enforcement
B. search our knowledge base for answers to all of your questions about the online world
C. report any incident of Internet use
D. help your brothers or sisters siblings learn how to avoid the dangers that exist on the
Internet.
58. Which of the following stories you can share on the Real-Life Stories?
A. Teen murdered by man she met in chat room.
B. Problem of losing weight.
C. Left home alone.
D. Hurt by second hand smoke in the Internet cafe.
答案

  55-58  CBCA

多项选择题
问答题

某市乡镇企业局下属A造纸厂法定代表人厂长李某因本地资源缺乏,纸浆生产能力不足,拟出售本厂现有2184板纸机一套,另行购人小型纸机。李某的表弟王某现任B科技开发公司总经理,得知此情况后,愿意代A造纸厂出售该2184型板纸机。李某与王某经协商,签订了合同,约定:1、A造纸厂委托B科技开发公司代理出售2184型板纸机一套,自立约之日起,A造纸厂不得未经受托人B科技开发公司同意私自与第三方直接洽谈出售该机事宜;2、该板纸机经双方议定价格为72万元,受托方对外转让超过此价部分,作为酬金归受托方所有。合同签订后,王某积极联系出售该板纸机,与C造纸厂签订了转让协议书。约定:B科技开发公司受A造纸厂委托,出售该厂所有的2184板纸机一套给C造纸厂,价格为105万元。C造纸厂派人验货后先付总价款20%的定金给B公司,其余货款在搬迁时付40%,剩余40%在C厂安装试运行完毕后付清。协议签订后,C厂为稳妥起见,向某市乡镇企业局询问是否有出售2184板纸机一事。乡镇企业局得知此事后,立即展开调查,查明李某出售2184板纸机未经乡镇企业局同意。根据该局规定,该局下属企业出售重要设备必须经过局党委讨论通过,因此,该局认为李某的擅自出售重要设备,且售价偏低,属违纪行为,决定撤销了李某的厂长职务。随后,乡镇企业局又指令A厂新任厂长刘某另行联系出售该2184板纸机。刘某经过联系,再次与C造纸厂订立合同,约定以90万元的价格将该板纸机出售给C厂,价款在拆卸机器时一次付清。C厂向A厂支付了约定的价金,取得了该板纸机。B公司得知此事后,以A厂、C厂为被告向人民法院提起了诉讼,请求法院撤销A厂和C厂直接签订的合同,并请求法院判令C。厂直接向其支付105万货款。被告A厂答辩称B公司与C公司订立的转让设备协议未经本厂同意,应属无效。C厂答辩称由于A厂告知其B公司订立的合同未经其同意,因此才与A厂另订合同,我方无责任。关于本案,回答下列问题:

B公司代理A厂与C厂订立的合同效力如何为什么