What to do...

[LastPoet]

No need to be a debater, just say you don't know, science is doing pretty well explaining stuff and helping us along the way, mabe it can someday answer those questions. When they start to mock you, ask them how do they know, and if they care to present the evidence for god first, since they are the ones with the burden of proof. When they say "The Bible" laugh, and turn away. Talking with teenage theists too much, dries your brain cells faster than with adult ones.