What is the name of the narrow bridge of land that connects north america to south america

Bering Strait is between North America (Alaska) and Asia - not South America. 

The correct asnwer is: Central America: this includes such countries as Costa Rica, Nicaragua and Panama, together with the Panama Canal which allows ships to cross from the Atlantic to the Pacific. hope this helps

Geothermic gradient is the rate of increasing temperature with respect to increasing the depth in the earths interior. away from tech tonic plates boundaries, it is about 25-40 c/km (72-87 degrees f/mi) of depth near the surface in most of the world.

Answer the above statement is (false) the correct answer is linear villages;