What is the earth's crust mostly made out of
- What is the earth's crust mostly made of
- What is the earth's crust mostly made up of
- What element is the earth's crust mostly made of
- What is the earth's crust mostly made of the land
- What rock is the earth's crust mostly made of
- What mineral is the earth's crust mostly made of
- What type of rock is the earth's crust mostly made of