Which of these structures relies on the circulatory system to transport the chemical compounds that it makes to other body structures

Me with biology endocrine system crossword also image left i need with hw

20 the compound al(nh3)2 has atoms of nitrogen.

Dr. arenas is a scientist who has been trying to determine if increasing pressure will increase the sound that occurs when two chemicals explode. it measures the volume of the sound that occurs at the minimum pressure at which the explosion will occur. it then increases the pressure and measures the volume of the explosions that occur. what kind of investigation is the scientist conducting?