Briefly at leat two issues that could lead social injustice

I think that the question could be rephrased as "briefly discuss at least two issues that could lead to social injustice"

my ideas:

-racism or other beliefs in the society that some people are better than others: this will introduce systematic bias (for example if everyone thinks women are better workers, men will be systematically left out)

-corruption: people in power could use corruption to strengthen their privileges.

The one that most represents the earths mantle would be the skin since the mantle is the upper part of the earths depths which is just like the skin of an apple.