Answer:
Challenges that stand in the way of sending explorers to the center of the earth are, the heat is way too intense, it would burn them up in a second, there is so much pressure that with the burning it would smash them.
Explanation:
By composition, group, and method of lithification. Composition is what its made of, group is whether the rock has grain of layers, and method of lithification is whether is was formed from compaction, cementation, etc<span />
Democracy is the correct answer.
they all have democratic government but different ways of democracy.
