large roomsshows the different ______ of genders.
　　38、 High densitymay reduce helping behaviour due to the ______.
　　39、 People feelless crowding if they can ______ more over the situation.
　　40、 The mosteffective way to reduce the effect of high density on human beings is ______.

　　参考答案：
　　V
　　I
　　III
　　VII
　　IX
　　II
　　IV
　　resourcelimitations
　　socialdensity
　　privacy
　　personalspace requirements
　　diffusionof responsibility
　　control
　　socialwithdrawal
　　答案仅供参考

　　Passage 2：
　　题材：动物
　　题型：选择+填空
　　题号：旧题
　　参考文章：
　　Ants could Teach Ants
　　The ants are tiny and usually nest betweenrocks in the south coast of England. Transformed into research subjects at theUniversity of Bristol, they raced along a tabletop foraging for food -- andthen, remarkably, returned to guide others. Time and again, followers trailed