大量事实表明，蛋白质合成旺盛的细胞中，常常含有较大的核仁。这一结果表明[ ] A

食管癌大多是（）。

A．腺癌

B．鳞状细胞癌

C．印戒细胞癌

D．黏液腺癌

E．小细胞未分化癌

由生活经验知道，在马路上骑自行车时，速度越大，感觉空气的阻力越大，小明同学根据这个经验提出了一个问题：空气阻力与速度有什么关系？

针对这个问题，他提出了如下猜想：

（1）也许空气阻力大小与速度大小成正比；

（2）也许空气阻力大小与速度平方成正比．

究竟哪一个猜想正确呢？他设计后进行实验，并获得如下数据：

                                    同一个物体

速度	1.0m/s	2.0m/s	3.0m/s	4.0m/s
空气阻力	5.0N	20N	45N	80N

小明对上述数据进行了归纳分析，得出初步结论，并验证了自己其中一种猜想是正确的．根据你刚才的阅读，请回答：

（1）小明得出的结论是______．

（2）回忆一下骑自行车减小阻力的场景，提出空气阻力还可能与什么有关？

答：______

（3）小明是按照怎样的思维程序进行探究活动的？

答：______、→______、→______、→______．

在研究物体运动时，下列物体中能当做质点处理的是（）

A.用GPS定位系统研究汽车位置时

B.研究“神舟八号”飞船绕地球运转时

C.研究乒乓球运动员张继科发出的乒乓球时

D.研究火车穿越一山洞所需时间

Passage Three

Watching movie stars light up on screen may increase the odds a child or young teen will try smoking, study findings suggest. In this latest study, researchers at Dartmouth Medical School in Lebanon, New Hampshire found that the odds of a child smoking increased in tandem (一前一后，紧密相连) with the number of films with smoking scenes he or she had seen. This pattern remained regardless of other smoking risk factors such as having parents or friends who smoked, poor school performance or a self-reported "rebellious" nature. Dr. James D. Sargent and his colleagues report the findings in the December 15th issue of the British Medical Journal. In response to the findings, the British Medical Association (BMA) called on the UK film industry to "stub out" on-screen smoking. "When smoking is glamorized in movies, young people are encouraged to experiment with a lethal (致命的) habit," the BMA’s Dr. Vivienne Nathanson said in a statement. And an editorial accompanying the journal report made the same challenge to Hollywood. "It is time for the entertainment industry to accept responsibility for its actions and stop serving the interests of tobacco companies," writes Dr. Stanton A. Glantz of the University of California, San Francisco. Sargent’s team based the findings on a survey of nearly 5 000 Vermont and New Hampshire students aged 9 to 15. Students were asked whether they had seen any of 50 recent movies that the researchers had screened for the number of smoking scenes. They also answered questions about environmental risk factors for smoking, their personality traits and perceptions of their parents’ views on smoking. The investigators found that the number of smoking instances students had seen in the movies was correlated with their odds of having tried smoking. Kids who had seen 51 to 100 smoking occurrences were 70% more likely than those who had seen fewer to have smoked. And the odds were nearly three times greater among those who had seen 150-plus smoking scenes. According to the researchers, the effects of on-screen smoking were similar to those of having parent or sibling who smoked. "The results indicate that exposure to tobacco use in films is pervasive," Sargent’s team writes. "More importantly, such exposure is associated with trying smoking, which supports the hypothesis that films have a role in the initiation of smoking. " In his editorial, Glantz agrees, writing that the study "provides powerful new evidence" that smoking in movies does contribute to adolescent smoking.

The subjects of Dr. Sargent’s study are ______.

A．college students

B．high school graduates

C．pre-school children

D．elementary and high school students

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