Trees get their mass from the air! They absorb CO2 (carbon dioxide) and use the Carbon to build their cells and release the excess O2 intt the air.
The plural of octopus are octopuses or octopi – both are grammatically correct.
The easiest way to differentiate a monkey from an ape is to look for it’s tail. If it has a tail, it’s a monkey, otherwise it’s an ape.