问题 问答题

某网络结构如下图所示,请回答以下问题。

采用一种设备能够对该网络提供如下的保护措施:数据包进入网络时将被进行过滤检测,并确定此包是否包含有威胁网络安全的特征。如果检测到一个恶意的数据包时,系统不但发出警报,还将采取响应措施(如丢弃含有攻击性的数据包或阻断连接)阻断攻击。请写出这种设备的名称。这种设备应该部署在图中的位臵1~位臵3的哪个位臵上?

答案

参考答案:

设备为:防火墙,位置为:位置2。

解析:

防火墙可以检查所有从外部网络进入内部网络和从内部网络流出到外部网络的数据包,并执行安全策略,限制所有不符合安全所要求的数据包通过。所以可以采用防火墙作为网络的入侵防护系统,布置在网络出口处,即位置2。

阅读理解

阅读理解。

     Americans have never before exercised and dieted as eagerly as they are doing today. As a result,

they do not only look younger and slimmer, but feel better. Because of increased physical fitness, life

expectance in the nation has risen to seventy-three years, with fewer people suffering from heart disease,

the nation's number one killer.

     Jogging ( 慢跑 ), the easiest and cheapest way of improving the body, keeps over 30million people

of all ages on the run. For the price of a good pair of running shoes, anyone anywhere can join the race.

Dieting, too, has become a national  pastime. Promoters of diets that eliminate eating one thing or another, such as fats or carbohydrates ( 碳水化合物 ), promise as much as 20- pound weight losses within two

weeks. Books describing such amazing diets always head up ( 居……之首 )the best-seller lists because people who are overweight want to lose weight quickly and easily.

     Nevertheless, jogging and dieting, carried to extremes, can be harmful. Many confused joggers

overdo and finally suffer from ankle and foot damage. Dieting, fortunately, becomes only a temporary

means for shedding a few  pounds while the body lose the balanced nutrition ( 营养 )it requires, so most

dieters cannot keep on diets. Above all, common sense should be the keystone for any dieting and

exercise plan.

1.The main idea of this passage is that ________ .

A. both jogging and dieting can improve your health

B. exercise and improved diet has raised the American's life expectance

C. people, who jog and diet wisely, will be healthier than those who do not

D. diet and exercise harm rather than benefit  health

2. According to the passage, which of the following statements is TRUE?

A. Jogging can damage the body because it is too tough an exercise.

B. Diets are so popular because they are on the best-seller lists.

C. Americans now live to be 73years old.

D. Exercise and diet are more widespread in America than ever before.

3. It is implied but not stated that ___________ .

A. heart disease is the number one killer among Americans

B. exercise and dieting bring about spiritual as well as physical well-being

C. people don't stay on a diet because it doesn't work

D. a 20-pound weight loss within two weeks is too much for the body

4. The best title for this passage is ___________ .

A. Jogging and Diet

B. Exercise and Health

C. Physical Fitness

D. Life Expectancy and Diet

判断题