The heat of the Earth's interior comes from which of the following sources?
a) radioactive elements
b) gravity
c) the sun
d) both a & b

This would be an open primary. a closed primary people can vote only prior to election day if the party if they are registered. independent voters can not participate. there is not a wide-open primary, but there is a semi-open primary.

Add the map and the options so i can further you, you so much. : )

From my point of view, the answer would be a.

C. england's numerous gold and silver mines made it a target for invasion