In fact, the reasons for the demise of the four ancient countries were all due to foreign invasion. The four major civilizations all have a common feature-when the civilization developed to the extreme, the military strength was not so good. Once the barbarians around them rose, the military strength was strong, and the ancient civilization was at another stage of development. It was the most fragile reform period, which may have neglected the deployment of military strength and eventually led to the demise of civilization. Moreover, it may be related to the environment. You see, Babylon died in the salinization period of Mesopotamia Plain, while China (my idea is that China was "after the cliff, fortunately there was Daming, but there was no China after Shen Jia") died in the so-called Cataclysm period (that is, the Little Ice Age at that time) and China was also engaged in the so-called cosmopolitanism, which was to let ethnic minorities adopt a policy of fending for themselves, thus laying the groundwork for the future. There are many reasons for the demise of the four ancient civilizations. At this time, the West is developing towards capitalism after the Renaissance and the bourgeois revolution, and China is a country that has gradually become ignorant under barbarian rule. How can the Chinese nation achieve a hundred years of humiliation?

Also, we really have to fight for that thing about South Korea, but we don't have to pay too much attention to it, because what is ours is ours, which is obvious to all. As for South Korea, with the support of the United States, she can only be brave for a while, and our historical accumulation is much deeper than theirs. This study shows that the landlord is actually the same as my previous point of view. It seems that the landlord is really a smart man, but there is really no need to get angry. I don't know if my answer satisfies the landlord.