Two mothers

Question: There are two mothers and two daughters. They go to a restaurant and ask for 3 chairs. Why?

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.