3 runners

Question: 2 men and a boy started a never ending race. One of the men can run super fast while the other man can run way faster than the boy. The boy is the slowest runner. What are they?

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?