题目

You probably know you should say” please” and “thank you ” at restaurants. You probably know the rules of a library. You know you should respect and be nice to your classmates. But do you have music manners? Keep It Down! You have to notice the volume of your music. You should not play your music so loud that everyone around you can hear it. Some people might even get angry. Usually, when you play the music loud on an MP3 player, other people can’t hear the words of the song. They just hear a loud sound. Not one wants to listen to this. Very loud music can also be bad for you如图在等腰梯形中，，，高，则腰的长为