问题 问答题 简答题

铁路信号分为哪几种?分别是怎样规定的?

答案

参考答案:

铁路信号分为视觉信号和听觉信号。

视觉信号的基本颜色:

红色——停车;

黄色——注意或减低速度;

绿色——按规定速度运行。

听觉信号:

号角、口笛、响墩发出的音响和机车、轨道车的鸣笛声。

阅读理解

阅读理解。

     In 2004, the World Health Organization, WHO, warned of a possible outbreak of another serious disease

which may be even more deadly than SARS. The WHO believes that it is likely that bird flu will spread to

human beings in the next few years. If it does, up to seven millions people could die from the disease.

     Diseases like bird flu are caused by viruses, that is, tiny things which change and become more dangerous

over time. When a new type of a common virus changes, it may be able to get past the body's immune system.

If that happens, humans are in great danger until a cure or treatment becomes available.

     There have always been viruses and people always get sick, of course, but as we saw with SARS, the

situation is more difficult today. People travel more than ever before, which means that disease can spread

quickly and across large areas-in fact the whole world.

     Scientists are already working on drugs that will prevent or limit the effect of a new virus, but the process

takes time. It is just as important to make sure that countries, especially poor countries, are prepared to deal

with the disease. New disease usually affect poor areas the most, so we must help develop health care in all

countries.

1. The situation is more serious today because _____.

A. people travel more

B. people don't eat health food

C. there aren't enough hospitals

D. scientists can't find a cure

2. From this passage we know _____.

A. bird flu will surely spread to human beings in the next few years

B. a virus changes and become less dangerous over time

C. SARS is 1ikely to come again in some years

D. poor areas usually suffers more from Dew diseases than rich areas

3. The possible title of this passage is _____.

A. The Work of WHO

B. Scientists Are Working Hard on Drugs for Diseases

C. What Is a Virus

D. Virus Changes and Causes New Diseases Over Time

判断题