In order for a nation to exist, the statement that must be TRUE is the country must be free to exercise sovereignty in handling its own affairs. The correct answer is D.
One important advantage that primary soruces have over secondary sources is that primary sources offer a firsthand account of an event - b, which isn't the case with secondary sources. Although this leaves primary sources prone to being biased compared to secondary sources.
Answer: The cheese melts on a hamburger because the burger has more thermal energy than the cheese, and because thermal energy travels from a warmer substance to a cooler substance, the cheese will melt due to substance reaction, and conduction coming from the hamburger onto the cheese when the cheese is placed on the hamburger.
Explanation: Because of thermal energy transfer. I hope I helped! :)
