Problem A and B help please

What chemical speeds up the process of decomposition in dead organisms are exposed to it? nitrogen oxygen hydrogen chlorine

Which description shows competition in an environment? an organism that feeds on some food an organism that finds a place to sleep three organisms of the same species living in an area three organisms battling over limited resources

High blood pressure occurs when there is too much blood flowing through the blood vessels at one time. by changing the amount of water in the blood, blood pressure can change. the excretory system can to lower blood pressure.which would most likely occur in the kidney? a)more water would be transferred from the nephron.b)less water would be absorbed into the nephron.c)the amount of water in the bladder would decrease.d)the amount of water in the blood would increase.