Question: When did Soong Ching-Ling's husband die?
Sentence (from "Sun Yat-sen"): Sun's chief legacy is his political philosophy known as the Three Principles of the People: nationalism (independence from foreign imperialist domination), "rights of the people" (sometimes translated as "democracy"), and the people's livelihood (sometimes translated as "socialism", or literally "a scientific study of helping people to survive in the society," as he explained the difference between his socialism and that of Karl Marx in his book.).
Relevant evidence: No