Answer:
Mechanical barriers — which include the skin , mucous membranes , and fluids such as tears and urine — physically block pathogens from entering the body. Chemical barriers — such as enzymes in sweat , saliva , and semen — kill pathogens on body surfaces.
90% of the available energy is lost in some form of heat, transferring light energy into different living organisms
The answer is C. Adapting to changes in the environment
It's a decomposition reaction. It's a chemical reaction because one substance (H2O2) is breaking down and becoming 2 completely new substances (H2O and O2)
