Is a ruby a mineral, gem, ore, or none

Alow pressure system is formed when an air mass cools over a cool surface and sinks. true or false

Name one type of data that h-r diagrams do not show.

If u make mistakes on a school trip to knotts like standing up on a ride too early and they ask you not to do it again or and if you do it again you will be escorted out will it go on my student record? yes i know it is a dumb question