Do they have common sense?
1) Mongolia conquered China.
Mongols killed 50% of the Chinese population.
"...According to the Chinese history not more than one hundredth part of the population survived, the countryside was covered with human bones, the cities left desolate..."
—“The Mongol Conquest Of China And Its Consequences”, by George Tait Edwards.
2)Mongols divided people into four classes, Chinese were the lowest.
1. Mongols 2. Semu people 3. Northern Chinese 4. Southern Chinese
---Society Under Mongol Rule, www.encyclopedia.com
3) Bayan, the Mongolian Grand Chancellor suggested killing all Chinese with one of the most popular surnames.
Bayan of the Merkid, Wikipedia
4) Genghis Khan’s Yassa.
“In cases of murder, one could ransom himself by paying fines which were: for a Mohammedan - 40 golden coins; and for a Chinese - one donkey (which was the cheapest).”
5) Marco Polo recorded that he met the Mongolian King, Kublai Khan, in Beijing.
When Mongols took Beijing, Mongols killed almost the entire population of Beijing, and used the dead bodies to cook human oil.
6) After Mongols conquered China, China became a part of Mongol Empire. The Chinese King was ordered to commit suicide.
Emperor Gong of Song, Wikipedia
7) Marco Polo recorded that Mongols called China as Manzi(barbarians).
As European and Arab travelers started reaching the Mongol Empire, …. Southern China, ruled by the Song dynasty (By the Chnese King), was (called) Mangi, Manzi, Chin, or Sin. The word Manzi or Mangi is a derogatory term in Chinese meaning "barbarians of the south" but it was adopted by the Mongols to describe the people and country of Southern China.
The name for South China commonly used on Western medieval maps was Mangi, a term still used in maps in the 16th century.
9) At the tome of Marco Polo, China was a part of Mongol Empire.
Please have a look at the map.