The answer is a. reunifying several kingdoms.
At the end of Tang Dynasty before Song Dynasty, The country was split into many kingdoms, the emperor of song dynasty also belonged to one of the kingdom. After his rise,he defeated the rest of the kingdoms one by one and finally reunifying the country.
Answer:
Since a drought in 1807-1808 caused a famine in the Dolores area and instead of releasing grain to market, Spanish merchants decide to hold it in storage, speculating on higher prices.
Answer:
Living on the Great Plains presented many challenges. The winters were bitter cold. There were few rivers and streams for water, and few trees for wood. Low rainfall caused drought and dust storms.