e.His writings were put into textbooks.

A.c-a-b-d-e　　　　　　　B.c-b-d-a-e

C.a-c-d-b-e D.a-d-b-c-e

　　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 teachers 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.No one wants to listen to that.Very loud music can also be bad for your ears,so even if you are alone when listening to your MP3 player,you shouldn't have it turned up too high.

　　Take Them Off!You need to know when to turn your MP3 player off and put it away.Libraries and schools don't allow MP3 players.There are other places,like museums,which don't have rules,but it would be rude to have your MP3 player on.Sometimes,it just doesn't make sense to listen to your MP3 player on public occasions.Why would you listen to music at a play,a movie or a sporting event?You would miss what is going on and others would wonder why you even came.

　　Take One Out!Once in a while it's okay just to take out one earphone and not the other.Imagine you are listening to your MP3 player when someone asks you the way.It would not be rude to take out one earphone,tell him the way,and put back the earphone and continue listening.You can also do this when you order food at a fast-food restaurant or when you answer the telephone and it's not for you.

　　It's Your Choice!There are times when you need to decide what is best.For example,some people can listen to music on their MP3 players when they read books,while others think it is disturbing.In cases like this,you need to do what seems right for you.

9．The underlined word "volume" in Paragraph 2 probably means " 　　　".

A.the type of music B.the amount of a sound