题目内容：

    “The calm before the storm” is a very familiar expression. It is usually used to describe a peaceful period just before a very stressful situation or a tense argument. 1. They noted that before certain storms the seas would seem to become calm and the winds would drop.

But why is it often so calm before a storm? 2. According to US website HowStuffWorks, a calm period occurs because many storms, tornadoes and hurricanes 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. 3. So once it covers an area, it causes a calm period before the storm.

4. First count how many seconds there are between a flash of lightning and a clap of thunder, roughly three seconds equal one kilometer. 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 ,calm doesn't always go first. So, your best bet is to keep yourself updated with weather reports for any predictions regarding a coming storm in your area. 5.

A. Science has given us the answer.

B. There is no definite answer to the question.

C. Weather reports sometimes cannot be trusted.

D. British sailors coined the phrase in the late l600s.

E. As the air declines, it becomes warm and dry, which is stable.

F. The Weather Network has a tip for working out how far away a storm is.

G. That's the most reliable way to predict the next display of nature's temper.