100. A compelling optical illusion called the illusion of velocity and size makes objects appear to be moving more slowly the larger the objects are. Therefore, a motorist’s estimate of the time available for crossing a highway with a small car approaching is bound to be lower than it would be with a large truck approaching.
The conclusion above would be more properly drawn if it were made clear that the
(A) truck’s speed is assumed to be lower than the car’s
(B) truck’s speed is assumed to be the same as the car’s
(C) truck’s speed is assumed to be higher than the car’s
(D) motorist’s estimate of time available is assumed to be more accurate with cars approaching than with trucks approaching
(E) motorist’s estimate of time available is assumed to be more accurate with trucks approaching than with cars approaching
100.
If the truck’s speed is assumed to be the same the car’s, then since the truck is larger, the optical illusion will make it appear that there is more time to cross the highway with the truck approaching than with the car approaching. Thus, choice B helps in establishing the conclusion and is the best answer.
If the truck’s speed is lower than the cars (choice A), the conclusion does not depend on the illusion. If the truck’s speed is higher than the car’s (choice C), the speed of the truck might counteract the illusion’s effect. Since the illusion works as stated regardless of what vehicle the estimate happens to be accurate for, neither choice D nor choice E assists in drawing the conclusions.
我对C答案为什么是错误的还是不是很理解，如果做选择我会选B，但是如果没有B我也不会认为C是错误的。 请大家给我指点一二，如何判断C是错误的啊？ 感谢了 | 
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发表于 2005-6-21 16:39:00
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