2．Why were bits of Abraham Lincoln's skull and bloody pieces of cloth collected?

　　A．To remember him.

　　B．To learn about his death.

　　C．To store for cloning in the future.

　　D．To be passed around like saintly relics.

　　解析：选B　推理判断题。根据第三段的"his doctors and friends collected bits of his skull and bloody pieces of cloth for autopsy (尸检)"可知，是为了了解Abraham Lincoln的死因。

　　3．What does the underlined word "futile" in Paragraph 4 mean?

　　A．Useless.　　　　 B．Interesting.

　　C．Exciting. D．Necessary.

　　解析：选A　词义猜测题。根据画线词后的"The hair itself would be very hard ... a complete follicle (毛囊)"可知，该词是指那些血迹和头发里的DNA可能已经"没用"了。

　　4．It's implied in Paragraph 4 that a complete follicle________.

　　A．doesn't have cells that die over time

　　B．is in Abraham Lincoln's remains

　　C．doesn't tell well about someone's genes

　　D．has one's entire DNA sequence

　　解析：选D　推理判断题。根据第四段的"The hair itself would be very hard to get the entire DNA sequence from unless you have a complete follicle"可知，完整的毛囊里面有完整的基因序列。

　　B

　　If you want to stay young, sit down and have a good think. This is the research finding of a team of Japanese doctors, who say that most of our brains are not getting enough exercise - and as a result, we are ageing unnecessarily soon.

　　Professor Taiju Matsuzawa wanted to find out why otherwise healthy farmers in northern Japan appeared to be losing their ability to think and reason at a relatively early age, and how the process of ageing could be slowed down.

　　With a team of colleagues at Tokyo National University, he set about measuring brain volumes of a thousand people of different ages and varying occupations.

Computer technology enabled the researchers to obtain precise measurements of the volume of the front and side sections of the brain, which relate to intellect (智力) and emotion, and determine the human character. (The rear section of the brain, which controls functions like eating and breathing, does not contract with age, and one can continue living without intellectual or emotional faculties.)