A positive effect of human interaction with the environment is : The large population increase

Using trees and vegetation for firewood

Herds if animals only grazing in the same place

The Panama Canal allowing for effective travel

The answer is a but it also might be 7 so

Its decreasing because of illnesses

The answer is 1-plate movement along fault lines

So  if  the sum of the enthalpies of the reactants is greater than the products, the  reaction  will be  exothermic.  if  the products side has a larger enthalpy, the  reaction  is  endothermic. you may wonder why  endothermic reactions, which soak up energy or enthalpy from the environment, even happen