What is the layer that is part crust part mantle?

What is the primary justification of the hypothesis that the early earth environment was void of oxygen? ( 2 points) data showing the concentrations of gases extracted from rocks fossil evidence regarding the origin of eukaryotes generally accepted atmospheric conditions molecular evidence based on evolutionary traits.

Which of the following is a reason why people are vacationing in slovakia

Which area on the map would be most likely to have the most oil exploration in since the start of the 21st century? a) b) c) d) plz me