题目内容：

    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 coined 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 infotainment (资讯娱乐) website HowStuffWorks, a calm period occurs because many storms, such as tornadoes and hurricanes, draw in all the warm and humid 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 descends, 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 rotating (旋转的) winds.

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 three seconds equal one kilometer. So, for example, if you count nine seconds, the storm is about 3 kilometers away. A good gauge (评估) 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 are preceded(先于) by calm. Given the right conditions, some storms announce themselves with heavy rain and chilling 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.The underlined word “static” in Paragraph 1 is closest in meaning to ______.

A.violent B.quiet

C.fast-changing D.warm

2.If there are 15 seconds between a flash of lightning and a thunder clap, how far away is the storm?

A.Three kilometers. B.Four kilometers.

C.Five kilometers. D.Six kilometers.

3.What can we learn from the last two paragraphs?

A.It is not always quiet before a storm.

B.Storms have a big influence on life.

C.Heavy storms don’t usually last for a long time.

D.Weather reports may fail to predict a storm.