参考答案：B

解析：[听力原文] 36-40 To quickly review the main points covered in Chapter 7, the most important part of the system of nerves is the brain. The brain controls most of the body activities. Messages between the brain and the spinal cord are carried by nerves, which are made up of special cells called nerve cells. Nerve cells are found in the brain, spinal cord, spinal nerves and in the organs we use to see, hear, smell, taste and touch. Nerve cells have long string-like fibres that carry messages. These fibres have branched ends to send and receive messages. Remember that nerve cells are so small that they cannot be seen without a microscope. But one fibre from the nerve cell may stretch as long as three feet. There are many kinds of nerve cells and this chapter deals mainly with three kinds. The sensory nerve cells carry messages of heat, light, sound, and pressure from the skin, muscles and organs inside the body. Motor nerve cells carry messages to the muscles and this causes the muscles to move. Connecting nerve cells go between the sensory nerve cells and the motor nerve cells to the muscles. All these different nerve cells help us see, hear, taste, smell and feel.

[分析]： 主旨题。 本文从大脑的功能谈起，强调其中的重要组成物质神经细胞，然后对其性质及功能进行详尽的说明。由此可见，B项内容“神经细胞的功能与性质”与原文相符，是正确答案。[解题关键] 根据文中关键词出现的频度可判断本文的中心。例如本文中短语nerve cells神经细胞频繁出现，暗示文章主题与此有关。