Good Riddles

Question: in all of written history I won't show up at the end of a sentence but I will be there in the end . . .

Question: why did the cops raid the orchestra pit?

Question: There are two persons. One is dead and one is still breathing. The dead one is called dead person. What did the other person call?

Question: Which kind of book can move by itself?

Question: Ben saw a very special bus. Its colour is yellow and purple. This bus can fit more than 99 persons. Guess where he saw that bus.