Tornadoes are powerful, swirling winds. Tornadoes can tear roofs off. They can smash brick buildings. Tornadoes can pick up cars and trucks.

Where do tornadoes come from?

Tornadoes come from big thunderstorms. Tornadoes drop down from the bottoms of storm clouds. Tornado winds blow in a circle. You can’t normally see wind, but you can often see a tornado. 【小题1】

A tornado looks like a big, dark funnel coming from the bottom of a storm cloud. Some tornadoes look like a swinging elephant’s trunk. They sound like a freight train going by.

Tornadoes cause damage 【小题2】

How large and fast are tornadoes?

Tornadoes can be huge. The biggest tornadoes are almost 1 mile (almost 2 kilometres) across.

The average tornado is about 160 feet (about 50 metres) across.

【小题3】They whip around at speeds from 75 miles per hour (120 kilometres per hour) to almost 300 miles per hour (500 kilometres per hour).

Tornadoes usually move. They can move forward at speeds up to 70 miles per hour (110 kilometres per hour).

【小题4】

Tornadoes can form anywhere, but they are more common in some places than in others. The United States gets the most tornadoes. Australia also gets many tornadoes. There are more tornadoes in spring than in any other season.

Tornado Alley is a place in the Midwestern United States where many tornadoes form. Tornado Alley goes from parts of Texas northward through parts of South Dakota. Another place that gets many tornadoes is Dixie Alley, 【小题5】

When Jack, my husband, and I drove past a fire station with a sign reading, “Are you ready for the next storm?” Our area had just been in the path of Hurricane Irma, causing downed trees and outages. We were stuck in the dark and cut off from the outside world.

We have had our share of storms in the past years — a snowstorm and other heavy snows that knocked down trees, sometimes up to a week at a time. Those days in a cold house weren’t fun, but we learned so much from those early storms, things that made later storms easier to bear.

Now we have stored up flashlights, lanterns and candles. We bought a battery-operated radio to keep up with the news. We stocked up on batteries so that we’d have plenty for extended power failures. We make sure our grill (烤架) is ready and its tank is full, and we purchase food that can be easily prepared and then cooked or heated on the grill. And we don’t forget to buy emergency chocolate! We have book lights to read in the dark. We keep our car gas tanks full and have emergency cash on hand.

We’re ready for the next storm, but we wouldn’t have learned to do all those things if we hadn’t encountered a storm in the past. The same is true spiritually. Those little storms in our lives are never fun, but they prepare us for the big storms — the big trials — that will come our way. They can teach us some valuable lessons.

Are you ready for the next storm? Now is the time to get ready, not when the storm arrives.

As sea levels climb, even Washington, D. C. could see more frequent and widespread flooding at high tide.

Strong storms and high winds sometimes bring floods to coastal areas. But cities and towns along the US East Coast are flooding even in calm and sunny weather. Among them is Maryland’s capital Annapolis. Tourists there must sometimes walk through water flooding downtown streets surrounding the harbor. Sometimes water covers roads in Atlantic City, N. J. Even the yards and basements of coastal homes near New York City sometimes flood.

All are suffering from this trend—normal high tides surpass (超过) a rising sea level.

Sea levels have climbed, on average, about 20 centimeters (8 inches) over the past 135 years. And a sharp increase in tide flooding is one of the more visible impacts affecting many coastal areas, notes William Sweet, an oceanographer.

Sweet and his co-workers recently analyzed data from 45 tide gauges (计量表) along the US coasts. These tools record the changing heights of tides as they rise and fall. From these data, Sweet’s team calculated the number of : “troublesome floods” in various coastal cities. These floods, Sweet explains, typically occur when water level is about 30 centimeters (1foot) above the historic level of the highest tides. In June 2014, the team reported finding a growing rise in these flooding events.

In Charleston, S.C. from 1957 to 1963, the city experienced troublesome floods an average of 4. 6 days per year. Bur from 2007 to 2013, the occurring rate of troublesome floods jumped five times. Annapolis city was even more serious. From1957 to 1963，troublesome floods were roughly 3. 8 days per year. From 2007 to 2013, the average was 10 times higher- 39. 3days a year.

“Over the next few decades, climate change probably drives sea levels even higher,” Sweet says. “So today’s flooding problems promise to become only more widespread and frequent.”