暴風(fēng)雨前的寧?kù)o

江蘇鹽城射陽(yáng)陳洋中學(xué) 溫從秀

幾乎每個(gè)人都聽(tīng)過(guò)“暴風(fēng)雨前的寧?kù)o”這句話，它通常用來(lái)形容非常緊張的情況或緊張的爭(zhēng)論之前的一段平靜的時(shí)期。 但為什么暴風(fēng)雨前總是那么寧?kù)o呢？ 科學(xué)給了我們答案。

題材自然現(xiàn)象體裁說(shuō)明文文章詞數(shù) 難度 建議用時(shí)361 ★★★ 6 分鐘

難詞探意

process /?pr??ses/ n. 過(guò)程；步驟

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.

Reading Check

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.

Language Study

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】________________________________

【點(diǎn)石成金】這是一個(gè)主從復(fù)合句，itispushed 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 是由連詞Once引導(dǎo)的條件狀語(yǔ)從句，其中it can from the air是限制性定語(yǔ)從句， 省略了關(guān)系代詞that及謂語(yǔ)動(dòng)詞take。