What is surface/strip mining?

What is the approximate chemical composition of the solar nebula?

Which statements describe cultural influences? florida is bordered by water on three sides. french is spoken in parts of louisiana. forests are cleared to provide space for cattle grazing. male children are encouraged to attend the university. the longest river on the continent is located here. birthdays are celebrated on january 1st. per capita income of northern buckland is more than $100,000.

What is the border between layers a through f and layer g called?