Question

In the second half of each year ,many powerful storms are born in the tropical Atlantic and Caribbean Sea .Of these , only about half a dozen produce the strong , circling winds of 75 miles per hour or more that give them hurricane status, and several usually make their way to the coast. There they cause millions of dollars of damage, and bring death to large numbers of people.

The great storms that hit the coast start as innocent circling disturbances (扰乱) hundreds or thousands of miles out to sea . As they travel aimlessly over water warmed by the summer sun, they are carried westward by the trade winds（信风）When con­ditions are just right , warm , moist air flows in at the bottom of such a disturbance , moves upward through it and comes out at the top . In the process, the moisture in this warm air produces rain, and with it the heat is changed into energy in the form of strong winds. As the heat increases , the young hurricane begins to swirl (旋转)in a counterclockwise（逆时针方向） motion.

The average life of a hurricane is only about nine days, but is contains almost more power than we can imagine. The energy in the heat released by a hurricane's rainfall in a single day would satisfy the entire electrical needs of the United States for more than six months. Water, rather than wind is the main source of death and destruction in a hurricane. A typical hurricane brings 6 to 12-inch downpours resulting in sudden floods. Worst of all is the powerful movement of the sea —the mountains of water moving toward the low—pressure hurricane center, the water level rises as much as 15 feet above normal as it moves toward shore.

1．When does an ordinary tropical storm turn into a hurricane?

    A．When it begins in the Atlantic and Caribbean Sea.

    B．When it hits the coastline.

    C．When it is more than 75 miles per hour.

    D．When its wind reaches 75 miles per hour.

2．What is the worst thing about the hurricane?

    A．The destructive effect of water.            B．The heat it releases.

    C．It lasts about nine days.                        D．Strong winds.

3．The counterclockwise swirling of the hurricane is brought about by_________.

    A．the low pressure center of the storm      B．the force of waves of water

    C．the trade winds                                    D．the increasing heat

4．Which of the following about the hurricane is true?

    A．It often occurs around June.

    B．It is not so powerful as that of storm born in the Caribbean Sea.

    C．It usually lasts about nine days.

       D．It can be easily detected and prevented.

Answer 1

DADC