Fear is the driver's constant companion, andtragedy can be just a step behind. Scarcely a man in the 500 does not carry the scars ofancient crashes. The mark of the plastic surgeon is everywhere, and burned skin is common.Sometimes a driver's scars are invisible, part of his heritage. Two young drivers, Billy Vukovichand Gary Bettenhausen, raced in their first 500 in 1968. Less than 20 years before, theirfathers also competed against one another on the Indy track—and died there.

　　All this the drivers accept. Over the years, they have learned to trust their own techniques,reflexes, and courage. They depend, too, on a trusted servant—scientific engineering. Thoughthey may not have had a great deal of schooling (an exception is New Zealand's BruceMcLaren, who has an engineering degree), many drivers are gifted mechanics, with a feelingfor their engines that amount to kinship.

　　A few top drivers have become extremely wealthy, with six-figure incomes from prizemoney, endorsements, and jobs with auto-product manufacturers. Some have businesses oftheir own. McLaren designs racing chassis (底盤). Dan Gurney's California factory manufacturedthe chassis of three of the first four ears in the 1968 Indy 500, including his own second placecar.

　　Yet money is not the only reason why men race cars. Perhaps it isn't even the majorreason. Three-time Indy winner(1961, 1964, 1967) A. J. Foyt, for example, can frequently befound competing on dirty tracks in minor-league races, where money, crowds and safetyfeatures are limited, and only the danger is not. Why does he do it? Sometimes Foyt answers, "It's in my blood. " Other times he says, "It's good practice. " Now and then he replies, "Don'task dumb questions. "

　　26. The statement "it is usually their nerves that go first" means_______.

　　A. at first they all have a nervous look

　　B. they often find they can't bear the tension even if they are in good condition

　　C. someday they find they can't make responses to any risk

　　D. they can continue their career at most until the middle 40s

　　27. It can be inferred that a car accident is often coupled with_______.

　　A. a plastic surgeon B. a companion

　　C. a risk D. a fire

　　28. The invisible scars of the drivers mentioned in the second paragraph refers to_______.

　　A. the regrets left by their fathers B. the fears left by their fathers

　　C. the cars left by their fathers D. the heritage left by their fathers

　　29. Bruce McLaren is different from most of the drivers in that_______.

　　A. he himself designs chassis B. he has an engineering degree

　　C. he manufactures chassis D. he is a gifted mechanic

　　30. A. J. Foyt often takes part in minor-league races for_______.

　　A. prize money B. blood test

　　C. cheers from the crowd D. enjoyment

　　參考答案：

　　26. B 27. D 28. A 29. B 30. D

　　When we analyze the salt salinity(鹽濃度) ofocean waters, we find that it varies only slightlyfrom place to place. Nevertheless, some of thesesmall changes are important. There are three basicprocesses that cause a change in oceanic salinity.One of these is the subtraction of water from theocean by means of evaporation. In this manner, thesalinity is increased, since the salt stays behind. Ifthis is carried to the extreme, of course, white salt would be left behind; this, by the way, ishow much of the table salt we use is actually obtained.

　　The opposite of evaporation is precipitation, such as rain, by which water is added to theocean. Here the ocean is being diluted (稀釋) so that the salinity is decreased. This may occur inareas of high rainfall or in coastal regions where rivers flow into the ocean. Thus salinity may beincreased by the subtraction of water by evaporation, or decreased by the addition of freshwater by precipitation.

　　Normally, in hot regions where the sun is very strong, the ocean salinity is somewhat higherthan it is in other parts of the world where there is not as much evaporation. Similarly, incoastal regions where rivers dilute the sea, salinity is somewhat lower than in other oceanicareas.

　　A third process by which salinity may be altered is associated with the formation andmelting of sea ice. When seawater is frozen, the dissolved materials are left behind.. In thismanner, seawater directly beneath freshly formed sea ice has a higher salinity than it did beforethe ice appeared. Of course, when this ice melts, it will tend to decrease the salinity of thesurrounding water.

　　In the Weddell Sea, the densest water in the ocean is formed as a result of this freezingprocess, which increases the salinity of cold water. This heavy water sinks and is found in thedeeper portion of the oceans of the world.

　　26. This passage mainly tells us about_______.

　　A. the analysis of the salinity of ocean waters

　　B. the causes of the variation in oceanic salinity

　　C. the importance of the changes in oceanic salinity

　　D. the different forms of salts in ocean waters

　　27.It can be known from the passage that increase in the salinity of ocean water is causedby______.

　　A. melting of sea ice B. precipitation

　　C. evaporation D. supplement of salt

　　28.Which of the following is not the cause of the decrease in the oceanic salinity?

　　A. Precipitation. B. Rain and snow.

　　C. Formation of ice. D. Addition of water by rivers.

　　29.Which of the following statements is TRUE according to the passage?

　　A. Oceanic salinity has great effect on sea life.

　　B. Many factors combine to cause changes in oceanic salinity.

　　C. The movement of the water is related to the amount of salt.

　　D. The temperature of the water has much to do with the oceanic salinity.

　　30.The purpose of mentioning the Weddell Sea is_______.

　　A. to give an example of cold-water salinity

　　B. to point out the location of deep waters

　　C. to make a comparison between hot-water salinity and cold-water salinity

　　D. to show that the water in the Weddell Sea varies in salinity from place to place

　　參考答案：

　　26. B 27. C 28. C 29. D 30. A