问题 单项选择题

电子商务应用系统主要包括支付网关系统、业务应用系统、用户及终端系统和______。

A.CA系统

B.KDC系统

C.加密系统

D.代理系统

答案

参考答案:A

解析: 本题考查点是电子商务应用系统的组成。电子商务采用层次化的体系结构。目前多认为电子商务体系结构由4个层次构成,由下向上各层次应该为:网络基础平台、安全保障、支付体系和业务系统。网络基础平台是电子商务在Internet上进行商务活动的基础平台。目前,我国有中国科技网(CSTNET)、中国公用计算机互联网(CHINANET)、中国教育和科研计算机网(CERNET)、中国联通互联网、中国网通公用互联网(CNCNET)等,它们都能提供互联网接入服务。消费者将自己的计算机接入Internet,在商家开设的“商店”,即电子商务网站上,就可以进行电子商务活动。 另外,安全系统通过CA安全认证体系及其他的安全技术,保证电子商务中的资金流和信息流的安全。支付系统完成交易之中的支付活动。目前一般有两种支付方式:一是传统的支付方式,即采用邮局汇款或当面付款等方式;二是网上支付方式,通过Internet来完成交易中的资金支付。电子商务业务系统完成电子商务中具体的业务功能,如在线谈判、网上定货、接收客户的反馈信息等。

选择题
阅读理解

阅读理解。

     For all the dinner table, a glass of milk seems to be a constant, at least it was when I was growing up.

It was widely believed that milk was integral in building strong bones and teeth. There's no doubt that

dairy products (乳制品), and milk in particular, are high in protein and calcium, and most milk products

are supplemented with Vitamin D and A.

     While it's well known that our bones need calcium, some studies suggest that high calcium intake

doesn't necessarily lower a person's risk for fractures (骨折). A Harvard study found that people who

drank two or more glasses of milk had no greater protection from breaking a bone than those who drank

a glass or less a week.

     There's no doubt that we need calcium. Some anti-dairy supporters claim that dairy can lead to heart

disease. Much of this claim is based on high fat and high dairy products, like cheeses and creams, which

may indeed contribute to cardiovascular problems. Some studies have linked high milk intakes with a risk

of prostate cancer; this seems to be caused by high-fat dairy products, not dairy in general.

     Although milk was always regarded as one of the most important thing we need for our bones, yet

least promoted, factors involved in strengthening bones. Perhaps we should think of dairy as less like a

nutrient and more like a food. If you like it, eat it. If not, find some others. Because some claims may not

be completely true, when I eat a cream, I'm not thinking about calcium, protein, or any such thing I'm

thinking delicious.

1. Which of the following is TRUE on the milk?

A. The more milk you drink, the more risk for fractures you might be.

B. The more milk you drink, the less risk for fractures you might be.

C. The less milk you drink, the less risk for fractures you might be.

D. There is no link between them.

2. Some anti-dairy supporters claim that dairy can lead to except _________.

A. cardiovascular problems

B. heart disease

C. prostate cancer

D. stomach cancer

3. The underlined words "some others" in the last paragraph refer to _________.

A. dairy products      

B. milk

C. food

D. cream

4. What's the author's attitude towards milk?

A. He doesn't like milk any more.  

B. He used to drink milk as a child.

C. He regards milk as a nutrient.      

D. He always cares about calcium, protein when he eats something.

5. We can learn from the text that _________.

A. All the claims are not completely true.      

B. High milk intakes can lead to cancer.

C. It's necessary for you to reduce milk intakes.    

D. Give up milk for your health.