How much light is there in the trench zone?

What Challenge encouraged nations to participate in land and forest conservation? What are the workshops at San Luis Rey? Why does Alex say the students are being used and are pawns in the Forbidden City? Who is often called father of our national Park system? What does Burj Khalifa mean in English? Which organization is a ruler who has full control in a country? Most mysterious ocean area between Florida Keys and Puerto Rico? At what foundry was the Liberty Bell first cast? Best Places to Go: West? What are two causes for variation in temperature and salinity of an estuary? Can crocodiles swim across the Atlantic Ocean? Where do mushers cross frozen ocean? Is Niagara Falls man made? What eats a deer in the boreal forest? How deep can a water stream get? Where is the Great Lakes Naval Memorial And Museum - Uss Silversides in Muskegon Michigan located? Where is the Red River Valley Museum in Vernon Texas located? What is smartest sea animal? What is the opposite of the ocean floor? Why is there a need to put sand on beaches?