Answer:
What are the three principles of the people?
The three principles of the people are :nationalism, democracy, and the livelihood of the people.
This ideology was developed by Sun Yat-sen to create prosperous nation.
Are these realistic in China?
No. China has a massive authoritarian power structure, in which the government owned almost all the resources in the country. The people do not obtain the right to free election, which do not fulfill the 'Democracy' Criteria from the three principles.
How about in today's world?
Absolutely. Those three principles are generally popular among the citizens, it should not be difficult to achieve.
Probably the biggest challenge for any other country in the world would be fulfilling livelihood of the people.
But it can be solved by having emphatic understanding toward the hardship that felt by our fellow citizens.
A.D = Anno Domini Latin for "year of our lord"
B.C.E = Before the Common Era
C.E = Common Era this is a synonym for A.D
I remember learning B.C and B.C.E mean the same although B.C.E is used more in Science to show respect spiritually. If a person is refering to Science they will most likely say B.C.E instead of B.C
...hope this helps.
Assuming that you're talking about the Fall of constantinople, where the crusaders were pictured as tiny men massacred by giants Ottoman, the crusaders identified is as an insult and far from the truth since the painting was massively exaggerated
Hope this helps