instruction:
In this task, you are given a question and a context passage. You have to answer the question based on the given passage.
question:
What did the principle of inertia do for general relativity?, Context: The concept of inertia can be further generalized to explain the tendency of objects to continue in many different forms of constant motion, even those that are not strictly constant velocity. The rotational inertia of planet Earth is what fixes the constancy of the length of a day and the length of a year. Albert Einstein extended the principle of inertia further when he explained that reference frames subject to constant acceleration, such as those free-falling toward a gravitating object, were physically equivalent to inertial reference frames. This is why, for example, astronauts experience weightlessness when in free-fall orbit around the Earth, and why Newton's Laws of Motion are more easily discernible in such environments. If an astronaut places an object with mass in mid-air next to himself, it will remain stationary with respect to the astronaut due to its inertia. This is the same thing that would occur if the astronaut and the object were in intergalactic space with no net force of gravity acting on their shared reference frame. This principle of equivalence was one of the foundational underpinnings for the development of the general theory of relativity.
answer:
one of the foundational underpinnings


question:
Who helped prepare?, Context: The Apollo astronauts were chosen from the Project Mercury and Gemini veterans, plus from two later astronaut groups. All missions were commanded by Gemini or Mercury veterans. Crews on all development flights (except the Earth orbit CSM development flights) through the first two landings on Apollo 11 and Apollo 12, included at least two (sometimes three) Gemini veterans. Dr. Harrison Schmitt, a geologist, was the first NASA scientist astronaut to fly in space, and landed on the Moon on the last mission, Apollo 17. Schmitt participated in the lunar geology training of all of the Apollo landing crews.
answer:
Schmitt


question:
what is the first nation mentioned?, Context: In 1991, US President George H. W. Bush awarded Hayek the Presidential Medal of Freedom, one of the two highest civilian awards in the United States, for a "lifetime of looking beyond the horizon". Hayek died on 23 March 1992 in Freiburg, Germany, and was buried on 4 April in the Neustift am Walde cemetery in the northern outskirts of Vienna according to the Catholic rite. In 2011, his article The Use of Knowledge in Society was selected as one of the top 20 articles published in the American Economic Review during its first 100 years.
answer:
United States