Passage Two

　　Swimming the English Channel requires a tremendous amount of courage and strength, as well as careful training and planning. The three main problems that a swimmer faces are the coldness of the water, the strong tides, and the roughness of the waves in the channel. Even in summer the temperature of the water is never warmer than 50 to 68 degrees, which is the reason most swimmers make their attempts in August when the water is usually warmest.

　　The main difficulty in training for channel swimming is becoming accustomed to the cold. Swimmers usually spend three to four months practicing in the channel, gradually lengthening the time each day until they can stay in the cold water ten or fifteen hours—a stretch in the last stages of training. As added protection against the cold, before they begin a channel crossing, the swimmers cover themselves with a layer of heavy, brownish axle grease, putting on coating 1/16 to 1/8 inch thick.

　　Much of the success in swimming the channel depends upon the timing with the tides. The direct distance from Cap Gris Nez in France to Dover England—across the narrowest part of the channel—is 2l miles, but the swimmer must go a much longer distance because he does not travel in a straight line in order to swim with the tide changes. Perfect planning and timing are necessary to avoid being caught by the turn of the tide just as he nears the other side. Boats equipped with radar now follow channel swimmers and help keep them on course with the tide changes.

　　Channel swimmers must face the swift currents that move in the channel. Often a swimmer will come within a mile of the shore when the tide changes, making it difficult or impossible to finish the event.

　　Some swimmers are swept so far of course that the swim from 30 to 45 miles in the process. Rough waves are also difficult to battle; channel waters are relatively smooth for only a few days each month, and even then there are likely to be dangerous cross current and sudden weather changes.

　　()6.In the passage, the answers can be found to all the following questions EXCEPT.

　　A.How does a swimmer get ready for a crossing

　　B.Why is timing so important to a channel swimmer

　　C.How far should a swimmer swim in crossing the channel

　　D.What risks does a swimmer run in crossing the channel

　　()7.The main aim in training for channel swimming is .

　　A.to be used to the water temperature in August

　　B.to learn to lengthen the practicing time each day

　　C.to be accustomed to being covered with grease as a protection

　　D.to be good at standing the long hours in cold water

　　()8.A successful channel swimmer is said to be the swimmer who .

　　A.keeps himself on course with the tide changes

　　B.chooses the narrowest way to the other side

　　C.takes a curving course，following a radar boat

　　D.times his crossing so that he may reach the other side before tide

　　()9.According to the passage, the radar boat is used for .

　　A.rescuing the swimmer from drowning when he is in danger

　　B.preventing him from being caught by the tide

　　C.equipping him for the dangerous crossing

　　D.giving him the right direction when a storm puts him off the course

　　()10.The passage is less concerned with showing.

　　A.careful training for channel crossing

　　B.how to overcome the roughness of the water

　　C.the difficulties caused by the swift currents

　　D.how to choose the best time for a crossing