A set of interacting parts forming a complex whole

Which statement accurately describes the relationship between air pressure, air density, or altitude? as altitude increases, pressure increases. as altitude increases, air density increases. air pressure and density are lowest at sea level. denser air exerts more pressure than less dense air.

Let the ed50 of a recreational drug be defined as the amount required for 50% of a test group to feel high or get a buzz. if the ed50 value of ethanol is 470 mg/kg body mass, what dose would a 70 kg party goer need to quickly consume in order to have a 50% chance of getting a buzz? 235 mg 470 mg 32,900 mg 35,000,000 mg

Air can be considered a mixture. which statement does not explain why?