Answer: The Central Nervous System and The Peripheral Nervous System
The excretory system is most likely to respond when an animal is thirsty in this way: B. by retaining body fluids.
Because the body doesn't get enough fluids to not be thirsty anymore, it retains whatever fluids it already has in it until the thirst is satiated.
D sediment lowers oceanic ph
A. Natural Selection. This is because the weeds that are not resistant to it die out before they can reproduce, but the resistant ones grow to maturity and then reproduce, passing down the resistance gene. Over time, the resistance gene would become a normal thing in weeds, while the non-resistant gene would not exist anyone, since the gene could not be passed on.
