The most exciting storms are the ones with flashes of lightning.Unfortunately,those are scarce,unless you are near the Catatumbo River in Northwestern Venezuela.Here,nature's grandest sound and light show is often seen, because it happens about 160 nights a year.And it lasts for as long as 10 hours at a time.And unlike other lightning storms that cause just one or two flashes,this one is with as many as 280 per hour.It is the highest in the world. Besides,each one of them is so powerful that each can power every light bulb in South America.Not surprisingly,they can be seen for almost 250 miles.Fishermen and sailors often use them to guide them across the waters during dark nights.
What's even more surprising is that the lightning has been happening above the same spot where the Catatumbo River meets Lake Maracaibo for thousands of years.The best part is that the show is different every night.That's because the color of the lightning changes,depending on the amount of water in the atmosphere.On dry nights,the lightning appears white.When the air is not dry,it helps split up the bright light into red,orange and even purple.
Strangely enough,though this has been going on for centuries,scientists have still not been able to figure out the cause of this phenomenon.Some say that the storms are the result of the interaction of the area's unusual topography（地貌）,wind and heat.Others,however,believe that the storms are caused by a kind of gas in the area.The locals simply think that it is the "spirit of Catatumbo" that lights up the night sky.
【小题1】
According to Paragraph 1,if we say something is scarce,we probably mean .| A．it is far away | B．it is very terrible |
| C．it can be hardly seen | D．it can be very dangerous |
【小题2】
We know that in Northwestern Venezuela, .| A．people daren't go out at night |
| B．it rains heavily almost every day |
| C．lightning is used to power light bulbs |
| D．storms with flashes of lightning are common |
【小题3】
What has the greatest influence on the colors of the lightning?| A．The spot of the lightning |
| B．The air of the lightning spot |
| C．The color of the environment |
| D．The level of water in the Catatumbo River |
【小题4】
From the last paragraph,we learn that .| A．scientists will no longer study the lightning storms there |
| B．locals know about the lightning storms better than scientists |
| C．heat in Northwestern Venezuela is different from any other place |
| D．the reason why such lightning storms happen there is still unknown |
