暴风雨前的宁静

温从秀

几乎每个人都听过“暴风雨前的宁静”这句话，它通常用来形容非常紧张的情况或紧张的争论之前的一段平静的时期。但为什么暴风雨前总是那么宁静呢？科学给了我们答案。

process /prses/ n. 过程;步骤

Almost everyone has heard the expression “the calm before the storm”. It is usually used to describe a peaceful period just before a very stressful situation or a tense argument.

British sailors created the phrase in the late 1600s. They noted that before certain storms the seas would seem to become static and the winds would drop. But why is it often so calm before a storm？

Science has given us the answer. According to US website How Stuff Works， a calm period occurs because many storms， such as hurricanes and tornadoes， draw in all the warm and damp air from the surrounding area. As this air rises into the storm clouds， it cools and acts as “fuel for the storm， like petrol in a car”.

Once the storm has taken all the energy it can from the air， it is pushed out from the top of the storm clouds and falls back down to ground level. As the air goes down， it becomes warm and dry.  Warm， dry air is stable， so once it covers an area， it causes a calm period before the storm. This same process also causes “the eye of the storm” in hurricanes and tornadoes. In these conditions，  the calm occurs in the center of the storm because of the strong winds moving in a circle.

The Weather Network has a tip for working out how far away a storm is. First， count how many seconds there are between a flash of lightning and a clap of thunder. Roughly 3 seconds equal 1 kilometer. So， for example， if you count 9 seconds， the storm is about 3 kilometers away. A good judgement is that if your count is below 30 seconds， you should seek shelter straight away.

However， due to the complexity of storm system， not all storms break after calm. Given the right conditions， some storms announce themselves with heavy rain and cold winds.

So， your best bet is to keep yourself updated with weather reports for any predictions regarding a coming storm in your area. That's the most reliable and sensible way to predict the next display of nature's temper.

1. What does the underlined word “static” in paragraph 2 probably mean？

A. Still. B. Warm.

C. Violent. D. Changeable.

2. What is the author's purpose in writing the text？

A. To find out how a storm comes into being.

B. To explain why a peaceful period occurs before a storm.

C. To prove whether the research on storm clouds is correct.

D. To show how dangerous a storm can be in certain situations.

3. If there're 15 seconds between a flash of lightning and a thunder clap， how far is the storm？

A. About 15 kilometers.

B. About 9 kilometers.

C. About 5 kilometers.

D. About 3 kilometers.

4. What advice does the author give to predict a storm？

A. Turning to a weather expert.

B. Learning to observe the clouds.

C. Tracing the latest weather report.

D. Watching your neighbourhood weather.

Difficult sentence

Once the storm has taken all the energy it can from the air， it is pushed out from the top of the storm clouds and falls back down to ground level.

【翻譯】

【点石成金】这是一个主从复合句，it is pushed out from the top of the storm clouds and falls back down to ground level是主句，Once the storm has taken all the energy it can from the air是由连词Once引导的条件状语从句，其中it can from the air是限制性定语从句，省略了关系代词that及谓语动词take。