Answer:
Koreans defended their kingdom from the Mongol invasion.
Explanation:
During 1231, Mongol king Ogedei Khan ordered an invasion in Korea against Goryeo empire. These invasions were consist of six campaigns throughout the Korean Peninsula, caused the tremendous cost of civilian life. Throughout campaigns, Korea became a tributary ally of the Mongol Empire (Yuan Dynasty) for about 80 years.
Infinitely many.
<span>45 + 45, 46 + 44, 47 + 43, ... , 98 + 1, 99 + 0, 100 + (-1), 101 + (-2) and so on and on and on. Without an end in sight.</span>
Helped determine our distance from the sun and might have an atmosphere, like Earth.
Runes are the letters of the alphabet used by the Norse Vikings (located in northern Europe).