单选题 Psychologist George Spilich and colleagues at Washington College in Chestertown, Mary-land, decided to find out whether, as many smokers say, smoking helps them to "think andconcentrate." Spilich put young non-smokers, active smokers and smokers deprived (被剥夺)of cigarettes through a series of tests.
In the first test, each subject (试验对象) sat before a computer screen and pressed a keyas soon as he or she recognized a target letter among a grouping of 96. In this simple test, smok-ere, deprived smokers and nonsmokers performed equally well.
The next test was more complex, requiring all to scan sequences of 20 identical letters andrespond the instant one of the letters transformed into a different one. Non-smokers were faster,but under the stimulation of nicotine (尼古丁) , active smokers were faster than deprived smok-ere.
In the third test of short-term memory, non-smokers made the fewest errors, bul deprivedsmokers committed fewer errors than active smokers.
The fourth test required people to read a passage, then answer questions about it.Non-smokers remembered 19 percent more of the most important information than active smokers,and deprived smokers bested those who had smoked a cigarette just before testing. Active smokerstended not only to have poorer memories but also had trouble separating important information frominsignificant details.
"As our tests became more complex," sums up Spilich, "non-smokers performed better thansmokers by wider and wider margins." He predicts, "smokers might perform adequately at manyjobs until they got complicated. A smoking airline pilot could fly adequately if no problems arose,but if something went wrong, smoking might damage his mental capacity."

单选题 The purpose of George Spilich' s experiments is______

A. to test whether smoking has a positive effect on the mental capacity of smokers
B. to show how smoking damages people' s mental capacity
C. to prove that smoking affects people' s regular performance
D. to find out whether smoking helps people' s short-term memory

【正确答案】 A

【答案解析】[解析] 参见文章第1段第2行。

单选题 George Spilieh' s experiment was conducted in such a way as to______

A. compel the subjects to separate major information from minor details
B. put the subjects through increasingly complex tests
C. check the effectiveness of nicotine on smokers
D. register the prompt responses of the subjects

【正确答案】 B

【答案解析】[解析] 依据文章第2段开头、第3段开头、第4段、第5段中的“The fourth testrequires people to…”以及第6段中的“As our tests became more complex…”，可知测试项目越来越复杂。

单选题 The word "bested" (Line 3, Para. 5) most probably means______

A. beat
B. envied
C. caught up with
D. made the best of

【正确答案】 A

【答案解析】[解析] 四个选项的意思分别为：A．“击败，战胜”；B．“妒忌”；C．“赶上”；D．“充分利用(机会和时间)”。该词出现的语境在第5段第3行。从该句的上下文可看出：non-smokers(不吸烟者)比active smokers表现好，deprived smokers要比测试前抽了一支烟的人表现好。

单选题 Which of the following statements is true?

A. Active smokers in general performed better than deprived smokers.
B. Active smokers responded more quickly than the other subjects.
C. Non-smokers were not better than other subjects in performing simple tasks.
D. Deprived smokers gave the slowest responses to the various tasks.

【正确答案】 C

【答案解析】[解析] 依据文章第2段第2行，在这个简单测试中，烟民、被剥夺抽烟权利的人和非吸烟者表现得一样好。说明：在从事简单任务时，非吸烟者并不比其他测试对象表现得更好。

单选题 We can infer from the last paragraph that______

A. smokers should not expect to become airline pilots
B. smoking in emergency eases causes mental illness
C. no airline pilots smoke during flights
D. smokers may prove unequal to handling emergency cases

【正确答案】 D

【答案解析】[解析] 依据文章第6段第4行可推论出：吸烟者在处理紧急事件时将被证明是不能胜任的。