If you want to stay young,sit down and have a good think．This is

If you want to stay young,sit down and have a good think．This is the research result of professor Faulkner,who says that most of our brains are not getting enough exercise and as a result,we are ageing unnecessarily soon. Professor Faulkner wanted to find out why healthy farmers in northern Japan appeared to be losing their ability to think and to reason at a relatively early age,and how the process of ageing could be slowed down. He set about measuring brain volumes of a thousand people of different ages and occupations． Computer technology enabled him to obtain precise measurements of the volume of the front and side sections of the brain,which relate to intelligence and emotion,and determine the human character． Contraction of front and side parts--as cells die off--was observed in some subjects in their thirties,but it was still not evident in some sixty-and seventy-year-olds. Faulkner concluded from his tests that there is a simple way to slow the contraction—using the head. The findings show that contraction of the brain begins sooner in people in the country than in the towns．Those least at risk,says Faulkner,are lawyers,followed by university professors and doctors．White--collar workers doing routine work are,however,as likely to have shrinking brains as the farm worker,bus driver and shop assistant. Faulkner's findings show that thinking can prevent the brain from shrinking．Blood must circulate properly in the head to supply the fresh oxygen the brain cells need．"The best way to maintain good blood circulation is through using the brain,"he says．"Think hard and engage in conversation．Don't rely on pocket calculators." Faulkner's research findings are based on__.
A、a survey of farmers in northern Japan
B、tests performed on a thousand old people
C、the study of brain volumes of different people
D、the latest development of computer technology
【正确答案】：C
【题目解析】：Faulkner教授的研究结果基于他对不同人的大脑体积的研究。文章明确提到：“He set about measuring brain volumes of a thousand people of different ages and occupations.” 这意味着他进行了一系列关于不同年龄和职业的人的大脑体积的测量。文章的其他部分也围绕这一研究展开，包括使用计算机技术获得精确的大脑前部和侧面部分的体积测量值，这些部分与智力和情感相关，并决定人的性格。因此，Faulkner教授的研究发现是基于对不同人的大脑体积的研究。 A选项“对日本北部农民的调查”虽然提到了研究的一个特定方面，但它只是Faulkner教授研究的一个起点，不是他的整个研究的基础。 B选项“对一千名老年人的测试”不准确，因为文章提到的是“一千个不同年龄和职业的人”，而不仅仅是老年人。 D选项“计算机技术的最新发展”是Faulkner教授在研究中使用的工具，而不是他研究的基础。 因此，正确答案是C：“对不同人的大脑体积的研究”。