Logic Riddles

Question: What is AD before BC, exams before tests and last year is after last month?

Question: I am the first son of my father, I can live without men but men can't live without me, the second son of my father has seen men rise and fall and have all of their secrets in his belly, the third son of my father can never give you his gift forever, he takes it from you when you corrupt it unknowingly but men cry for his gift no matter its cost, the fourth son of my father is an obedient servant in the hands of men but when he losses his master he becomes an unmercifully god, the fifth son of my father is the center of our lives, he guides us but he is a divine mystery. What are we?

Question: There are three books on a shelf standing side by side. Each book is 10ml thick. The bookworm eats its way through the first page of the first book to the last page of the last book. How far did the bookworm move if it can only move in a straight horizontal line?

Question: There were 2 children, the son and the daughter. The daughter was born on January 20th and the son was born on March 12th. Both of them were born in the morning. Which one did their parents see first?

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 . . .