问题
单项选择题
关于电子商务系统结构中安全基础层的描述，以下哪种说法是错误的？
A．安全基础层位于电子商务系统结构的最底层
B．安全基础层用于保证数据传输的安全性
C．安全基础层可以实现交易各方的身份认证
D．安全基础层用于防止交易中抵赖的发生
答案
参考答案：A
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关于电子商务系统结构中安全基础层的描述，以下哪种说法是错误的？
A．安全基础层位于电子商务系统结构的最底层
B．安全基础层用于保证数据传输的安全性
C．安全基础层可以实现交易各方的身份认证
D．安全基础层用于防止交易中抵赖的发生
参考答案：A
| Reading newspapers has become an important part of everyday life. Some people read newspapers as the first thing to do in the morning, others read newspapers as soon as they have free time during the day so that they can learn what is happening in the world. Sometimes, we do not have enough time to read all the news carefully, so we just take a quick look at the front page. At other times, we may be in such a hurry that we only have a few minutes to look at the headlines (标题) of the passage. Newspapers can be found everywhere in the world. We can get many different kinds of newspapers in big cities, but in some mountain villages we can see few newspapers. Some newspapers are published (出版) once a week, but most of the papers are published once a day with many pages, some even published twice a day! You know different people enjoy reading different newspapers. Some like world news, and others prefer short stories. They just choose what they are interested in. Today newspapers in English have the largest numbers of readers in the world, The English language is so popular that many Chinese students are reading English newspapers such as China Daily or 21st Century. Also they bring us more and more information with internet. |
| 1. People read newspapers in order to . |
[ ] |
| A. learn the latest news B. meet their own different needs C. read the short stories D. find the morning news |
| 2. From the passage we can see that when people get newspapers. |
[ ] |
| A. they read them very carefully B. they just read the headlines C. not everyone reads all the pages D. they have no time to read them |
| 3. According to the passage, besides newspapers, people also get information from . |
[ ] |
| A. magazines B. advertisements C. e-mails D. internet |
用试纸检验气体性质是一种重要的实验方法．如图所示的实验中(可加热)，下列试纸的选用、现象、对应结论都正确的一项是
试剂B | 湿润的试纸A | 现象 | 结论 | |
| A. | 碘水 | 淀粉试纸 | 变蓝 | 碘具有氧化性 |
| B. | 浓氨水，生石灰 | 蓝色石蕊试纸 | 变红 | 氨气为碱性气体 |
| C. | Na2SO3，硫酸 | 品红试纸 | 褪色 | SO2具有漂白性 |
| D. | Cu，浓硝酸 | KI淀粉试纸 | 变蓝 | NO2为酸性气体 |