Unit 1　The world of our senses

　　我们都知道人有五种感觉器官。不过，你熟悉五官的功能吗？了解它们是怎样产生作用的吗？

　　How do your senses work?

　　What's that smell？Do you hear that noise？Taste this！Look at me！Feel this，isn't it soft？When you hear，or even use these phrases，you probably don't stop to think about why we use them. Well，it's because of our sense. Without us even knowing，our sense organs (nose，eyes，ears，tongue，and skin) are taking in information and sending it to the brain for processing.If we didn't have them，we would not be able to smell，see，hear，taste，or touch anything!

　　Senses are the physical means by which all living things see，hear，smell，taste，and touch. Each sense collects information about the world and detects(发现) changes within the body. Both people and animals get all of their knowledge from their senses，and that is why senses are so important.

　　All senses depend on the working nerve system. Our sense organs start to work when something stimulates special nerve cells，called receptors，in a sense organ. Once stimulated，the receptors send nerve impulses(脉冲) along sensory nerves to the brain. Your brain then tells you what to do. For example，your sound receptors are often attacked by billions of sound waves. When these signals reach the part of the brain called the cerebral cortex(大脑皮层)，we become conscious of the sounds.

1．take in 　　吸收，接受；领会