Does anyone know and wanna help

Given: circle a externally tangent to circle b. how many possible common tangents to circles a and b can exist? 2 3 4

Never mind alrwady found the answer im looking for

What's a recharge area? a. the part of an aquifer where groundwater meets a lake or stream b. the part of an aquifer where surface water reaches the water table c. the part of an aquifer that's located between two aquicludes d. the part of an aquifer that's located at a lower elevation