Tornadoes are storms with very strong turning winds and dark clouds. These winds are perhaps the strongest on earth. They reach speeds of 300 miles per hour. The dark clouds are shaped like a funnel − wide at the top and narrow at the bottom. The winds are strongest in the center of the funnel.

Tornadoes are especially common in the United States, but only in certain parts. They occur mainly in the central states.

A hot afternoon in the spring is the most likely time for a tornado. Clouds become ( 1 ). There is thunder, lightning, and rain. A cloud forms a funnel and begins to twist. The funnel moves faster and faster. The faster the winds, the louder the noise. Tornadoes always move in a northeastern direction. They never last ( 2 ) than eight hours.

A tornado’s path is ( 3 ), but within that narrow path a tornado can destroy everything. It can smash buildings and rip up trees. Tornadoes can kill people as well.

The ( 4 ) tornado swept through the states of Missouri, Illinois, and Indiana in 1925, and it killed 689 people. Modern weather equipment now makes it possible to warn people of tornadoes. People have a much ( 5 ) chance of protecting themselves. But nothing can stop tornadoes from destroying everything in their path.

ア. better

イ. worst

ウ. longer

エ. dark

オ. narrow