单项选择题
Why is the Europe Commission wary of encouraging Gypsies to present themselves as a nation
单项选择题 The title that best expresses the ideas of this passage is ______.
单项选择题 According to the author, one possible reason for the growth of science during the days of the ancient Greeks and in modern times is ______.
单项选择题 The difference between "fact" and "theory" ______.