Section B
Passage One
How much living space does a person need? What happens when his space requirements are not adequately met? Sociologists and psychologists are conducting experiments on rats to try to determine the effects of overcrowded conditions on man. Recent studies have shown that [26]the behavior of rats is greatly affected by space. If rats have adequate living space, they eat well, sleep well, and reproduce well. However, if their living conditions become too crowded, their behavior pattern and even their health perceptibly change. They cannot sleep and eat well, and signs of fear and tension become obvious. [27]The more crowded they are, the more they tend to bite each other and even kill each other. Thus for rats, population and violence are directly related. Is this a natural law for human society as well? [28]Is adequate space not only desirable, but essential for human survival?

Questions 26 to 28 are based on the passage you have just heard.
26. What affects rats' behavior?
正确答案：C
解析：听到“最近研究表明：鼠类行为受空间影响颇大”，可判断C（空间）正确。
27. What effect may inadequate living space have on rats according to the passage?
正确答案：B
解析：原文说，空间越拥挤，老鼠就越容易相互撕咬和残杀，故B正确。A、C是积极健康的行为，而B、D则是不健康的行为。根据本文主题也可排除A、C，短文也未提及“自杀”，可排除D。
28. What is the experiment done on rats intended to prove?
正确答案：C
解析：短文介绍了有关老鼠的实验后提出，对老鼠而言，老鼠数量和暴力之间具有直接的关系。作者进而问道：这是否也适用人类社会？足够的空间是否也是人类生存所必需的条件？故对老鼠的研究是为人类服务的，C正确。