If you ears are working well，you hear sounds all the time．You can't switch（关掉）your ears off，even when you are asleep．

Listening

When you really want to listen to something，you tell brain to focus on that sound．If your ears are healthy and are both working well，they can turn down other sounds while you focus on what you want to hear．If one ear isn't working the other，they can't do this as well．If you hearing cells（细胞）have been damaged by too much loud noise or music，what you want to hear can get mixed up and lost in the other sounds around．With healthy ears you can choose what you want to listen to，but you can't choose what you hear．

Understanding

Your brain deals with the received sounds and tells you what they mean．Some people have problems understanding what they are hearing because their ears don't work well and they don't hear all the sounds．They brain does not get enough information to understand the messages or they may be mixed up．

Selective（选择的）hearing

Lots of mums and dads think that kids have this"problem"．They think that you select what you are going to hear and what you can't hear!Many mums say that dads do this，too．In fact，this is something we may all do to try and make our lives a bit easier．Some children wrote what they liked to hear and what they didn't like to hear．

76．What is the passage mainly about？（Please answer within 10words．）___

77．Please fill in the blank in Paragraph 2with proper words of phrases to complete the sentence．（Please anser within 3words．）___

78．What does your brain do when you are listening？___

79．Which of the suggestions do you think is the most important for you？Why？

（Please answer within 25words．）___

80．Translate the underlined sentence in the second paragraph into Chinese．___．