The first and second laws of thermodynamics relate to . energy flow and transformation
the insulation of heat
the active movement of the internal Earth
recycling of matter

answer; i believe the correct answer is ( proteins );

explanation:

on disadvantage of hydroelectric power is the cost. another disadvantage of using hydroelectric power is finding a water source powerful enough to harvest hydroelectric power.

after receiving a stimus, the sensory receptors send(s) signals to the appropriate area of the body.  

the must be sensory neurons.  

hope its .