问题 单项选择题

电子商务采用层次化的体系结构,支付型电子商务体系结构的四个层次从下至上为

A.网络基础平台、安全保障、支付体系和业务系统

B.安全保障、网络基础平台、支付体系和业务系统

C.网络基础平台、支付体系、安全保障和业务系统

D.网络基础平台、支付体系、业务系统和安全保障

答案

参考答案:A

解析: 电子商务的体系结构可以分为网络基础平台、安全结构、支付体系和业务系统4个层次。从下至上的排序,最低层的是网络基础平台,而最顶层的是业务体系。

单项选择题

Behind our house is the start of a fascinating trail (小径). This trail is one of the old roads that wind through untold miles of forest. My (36) , Beans, and I walk the trail frequently. Normally, Beans sniffs alongside the trail to follow the smell of a deer track or explore some cause known only to him.

Beans is a white dog, quite handsome and very smart. He not only understands what we tell him, but also often makes sounds as if he were trying to (37) back.

One morning, we took a different route, which led us to an unfamiliar trail. I was sure this trail would eventually lead us to our familiar (38) . But, no. We seemed to be far off course. After two hours, I suddenly realized that Beans probably (39) the way home. So I urged, "Beans, take me home." He ran down a new trail. But it merely led to an intersection (岔道口) of trails.

Soon it became (40) that we were getting nowhere. I began to picture the rest of the day in the (41) , without food or drink. We had walked about ten miles. But Beans seemed totally (42) The sniffing and exploring was going well for him.

Finally, we (43) a crossroad near a highway. Lady Luck suggested I should turn left. We did and (44) reached a cottage beside a field. I knocked on the door and explained my situation to an old man. He laughed and then drove us home.

Since our adventure, I (45) that Beans probably knew all along how to get home.

He was just having too much fan exploring new trails.

44()

A.punctually 

B.frequently 

C.formally 

D.shortly

单项选择题