5、There are two key elements to Nadal’s victories over Federer--speed and left-handed ground strokes.

       If tennis court surfaces get any faster, left-handed Rafeal Nadal, may eventually dominate（支配）right-handed Roger Federer, for the simple reason that left-handed sportsmen in general have naturally quicker reflexes（反应）.

       French sports researchers, led by Dr. Guy Azemar, are convinced, after 15 years of experiments, that the growing domination of left-handers in tennis can no longer be put down to their unorthodox（非正统的）technique. They say that everything points to left-handers having several thousandths of a second more time to react.

       The researchers were struck by the disproportionate(不相称的) success of left-handers. Left-handers dominate at the top although 90 percent of people are right-handed. Of the world's200 top tennis players, 16 percent are left-handed but five of the top 20 and three of the top four are left-handers. Federer, therefore, is considered to be an exception--a right-hander who can make up with technique what he loses in reflex.

       Dr. Azemar is convinced that the advantage is explained by the way messages are carried from the brain. "We want to show that the sorts of information needed in sport-speed and direction of attack-are treated by the right-hand side of the brain which handles the organization of time and space," he said. "With left-handers the message is transmitted direct to the left-hand side of the brain first, the side which treats logic. Then it is passed to the other side causing a loss of thousandths of seconds. "

1．It is implied in the first two paragraphs that              .

       A．Nadal is a better player than Federer

       B．Nadal can play as well as Federer

       C．Federer has naturally quicker reflexes

       D．Nadal has naturally quicker reflexes

2．The increasing domination of left-handers in tennis                       .

       A．was once considered the result of unorthodox technique

       B．is possible after 15 years of experiments

       C．is due to their unorthodox technique

       D．can no longer be controlled

3．How many left-handers are there among the world's 200 best tennis players?

       A．16                      B．20                       C．32                      D．90

4．The author suggests, but does not directly say, that Federer wins because           .

       A．he uses right hand                                                               B．he is the best player

       C．he has quicker reflexes                         D．he has better technique