Protestant denominations refer to as a group of protestant congregation like charismatic, Adventists and Lutherans. They are prevalent in North America, Australia and Africa
Are there multiple choices?
I would say D) Geology. That's a whole other subject itself. Economics, geography, and history all fit into the category Social Studies. That is things happening around the world. Social stuff. Hence the name Social Studies. So once again, D is your answer. Geology is about the science that deals with the earth's physical structure and substance, its history, and the processes that act on it.<span> The geological features of an area.</span> That would not fit in.
~Silver
The correct answer would be the second option. The correct plan for his experiment would be that the temperature, the type of limestone, and the type of acid are controls. The amount of acid and the amount of damage to the limestone are variables. To determine the degree of damage of the acid it would be best that the amount of acid is the manipulated variable while everything else are assumed constant.