How can friction be reduced and increased? explain with some examples

The friction can be increased by making the surface more rough

and it can be reduced by lubricating the surface ( making it smoother ) using lubricants ( oil, grease etc. )

well first you need the sample of the temperature and gas level. i couldnt write a hypothesis unless i had some data. i think temperature changes will effect volumes of gas because gas changed into a solid or liquid at specific temperatures.

answer; (a) medicalized;