What would happen if you rubbed a piece of fluorite against a piece of feldspar

Which of the following about topsoil is fake?

Can someone me choose a broad topic and area of focus i am really doing this as a tally to see which one most people pick ok water pollution global warming endangered species atmosphere for the !

What id the primary human cause of the global warming a. storage of nuclear fuel rods b. burning of fossil fuels c. building of high-density housing d. violent conflicts over natural resources