I Don't see any multiple choice answers but i'm going to take a gander and guess that the answer you are looking for is "<u>Coal</u>"
The sectional crisis among the southern and the northern states was how to incorporate vast territories in the nation and whether states would be slave or non slave.
<u>Explanation:</u>
From the time of 1848 to 1860, there were sectional crisis in the United States of America. The problem was how to inculcate vast territories in the nation after the end of the American Mexican war. Moreover the political tension was that whether the states would be slave or non slave.
The southern states favored the slavery as a fact of life while the northern states were against slavery and wanted better and equal lifestyle for the slaves also. Moreover the northern states were rich and the southern were poor and had lesser number of factories compared to north.
The Tang and Song rule is described to be the reunification and renaissance in Chinese civilization mostly due to the fact of military advancements, rapid expansion, the Civil Service Exams and taxation methods that developed over time. Li Yuan, Duke of Tang, established the golden age of Tang because of his rapid expansion and strong Chinese bureaucracy. The Civil Service exams created opportunities for families to raise their rank in the social and political hierarchy. The Song dynasty valued scholars over military, making them weak to invaders yet highly cultural and innovative.
