问题 单项选择题

下面说法正确的是______。

A.通信子网连接网络上的各种计算机,完成数据的传输、交换和通信处理
B.资源子网主要包括连网的计算机、终端、外部设备、网络协议和通信控制软件等
C.通信子网主要包括通信线路、网络连接设备、网络协议和通信控制软件等
D.资源子网收集、存储和处理信息,为用户提供网络服务和资源共享功能等

答案

参考答案:B

解析: 从系统功能的角度看,计算机网络主要由资源子网和通信子网两部分组成。从软件上来讲,它们都包含网络协议,不同的是资源子网还需要网络软件——因为它要为用户提供网络服务和资源共享功能,通信子网需要的则是通信控制软件一一因为它要连接网上的各种计算机,完成数据的传输、交换和通信处理;从硬件上来讲,资源子网包括的是连网的计算机、终端和外部设备,通信子网包括的是通信线路和网络连接设备——这也同样是由它们所要完成的功能决定的。

单项选择题

It seems that politicians around the world are thinking about the health of their countries. While in China, Chen Zhu has announced his plans for a universal health service and reform across health services. Gordon Brown, the UK Prime Minister, has also announced he is planning to make some changes in our health service.

The crux of Mr. Brown’s proposals is related to giving the NHS ( National Health Service) a greater focus on prevention, rather than just curing patients.

He is planning to introduce increased screening for common diseases such as heart disease, strokes and cancer, for example, breast cancer. In Britain there are 200,000 deaths a year from heart attacks and strokes, many of which might have been avoided if the condition had been known about.

Initially, the diagnostic (诊断的) tests will be available for those who are vulnerable, or most likely to have the disease. One example is a plan to offer all men over 65 an ultrasound test to check for problems with the main artery (动脉), a condition which kills 3,00Omen a year. The opposition have criticized Mr. Brown’s proposals, saying that they are just a trick, and claiming that there is no proper timetable for the changes. They also say that Mr. Brown is reducing the money available for the treatment of certain conditions while putting more money towards testing for them.

The NHS was founded in 1948, and is paid for by taxation. The idea is that the rich pay more towards the health service than the poor. However, in recent years there has been a great increase in the use of private health care, and it’s much quicker. The NHS waiting lists for operations can be very long, so many people who can afford it choose to pay for medical care themselves.

The author of this passage intends to tell us().

A.the NHS should be reformed right away

B.more and more people are dying from diseases

C.the plan to reform the NHS in the UK

D.the criticism of Mr. Brown’s proposals

单项选择题