Question: Losing the First Sino-Japanese War of 1894–1895 was a watershed. Japan, a country long regarded by the Chinese as little more than an upstart nation of pirates, annihilated the Qing government's modernized Beiyang Fleet, then deemed to be the strongest naval force in Asia. The Japanese victory occurred a mere three decades after the Meiji Restoration set a feudal Japan on course to emulate the Western nations in their economic and technological achievements. Finally, in December 1894, the Qing government took concrete steps to reform military institutions and to re-train selected units in westernized drills, tactics and weaponry. These units were collectively called the New Army. The most successful of these was the Beiyang Army under the overall supervision and control of a former Huai Army commander, General Yuan Shikai, who used his position to build networks of loyal officers and eventually become President of the Republic of China.
Is there an answer to this question: Who became the President of the Republic of China?

Answer: General Yuan Shikai


Question: Like most of southern California, the majority of San Diego's current area was originally occupied by chaparral, a plant community made up mostly of drought-resistant shrubs. The endangered Torrey pine has the bulk of its population in San Diego in a stretch of protected chaparral along the coast. The steep and varied topography and proximity to the ocean create a number of different habitats within the city limits, including tidal marsh and canyons. The chaparral and coastal sage scrub habitats in low elevations along the coast are prone to wildfire, and the rates of fire have increased in the 20th century, due primarily to fires starting near the borders of urban and wild areas.
Is there an answer to this question: Where can one find the most sage scrub in San Francisco?

Answer: unanswerable


Question: As African states became independent in the 1960s, the Soviet Union offered many of their citizens the chance to study in Russia. Over a period of 40 years, about 400,000 African students from various countries moved to Russia to pursue higher studies, including many Black Africans. This extended beyond the Soviet Union to many countries of the Eastern bloc.
Is there an answer to this question: Why did students move to Russia?

Answer: to pursue higher studies


Question: In quantum mechanics, energy is defined in terms of the energy operator as a time derivative of the wave function. The Schrödinger equation equates the energy operator to the full energy of a particle or a system. Its results can be considered as a definition of measurement of energy in quantum mechanics. The Schrödinger equation describes the space- and time-dependence of a slowly changing (non-relativistic) wave function of quantum systems. The solution of this equation for a bound system is discrete (a set of permitted states, each characterized by an energy level) which results in the concept of quanta. In the solution of the Schrödinger equation for any oscillator (vibrator) and for electromagnetic waves in a vacuum, the resulting energy states are related to the frequency by Planck's relation:  (where  is Planck's constant and  the frequency). In the case of an electromagnetic wave these energy states are called quanta of light or photons.
Is there an answer to this question: What describes the space-and-time dependence of a slowly changing wave function of quantum systems?

Answer:
The Schrödinger equation