OG5 阅读 Q41

Choice D is the best answer. In the passage Watts notes that "the category of the news items . . . had a strong effect on how much people could be manipulated" (lines 76-79,"in...is"). That idea is directly supported by the data in the figure, which show that the difference in mean score between the control comments and the artificially up-voted comments varies by subject (for example, in the general news category there is virtually no difference between the mean scores of the two types of comments, while for the business category there is almost a 1.0-point difference between the mean scores). 
Choices A and B are incorrect because the passage provides no data for artificially down-voted comments or negative social influence. Choice C is incorrect because the figure applies only to one context (mean score of control comments versus mean score of artificially up-voted comments on the news site); there is no way to tell what patterns would be observed in other contexts.