Cops

Question: one day there were two cops, they got a call saying there was some kind of mystery so they went to the house were the mystery was at, the lady there said she could not figure out how many letters the special word was, later the cops went home knowing that they had done a good job. How many letters was the special word?

Question: People see through me, but none pass through without killing me. I can be anywhere, and can be seen double or single. What am I?

Question: During what month do people sleep the least?

Question: When is 99 more than 100?

Question: What can be broken but never forgotten?

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