The hardest Riddle

Question: Tall as a tree, dressed in white, my bridal veil is shiny bright Up all night, never sleeping: if i rest, many are weeping. Upon the shores since the days of old, my silent message what am i?

Question: A girl dove in the sea.. some say there are two people under the sea. Why is that?

Question: Surrounded by life , yet life is its biggest enemy. But without life there is no need for it to exist. What is it?

Question: During what month do people sleep the least?

Question: When is 99 more than 100?

Question: The more you add, the less it weighs.