Question: The rapid expansion of the Rus' to the south led to conflict and volatile relationships with the Khazars and other neighbors on the Pontic steppe. The Khazars dominated the Black Sea steppe during the 8th century, trading and frequently allying with the Byzantine Empire against Persians and Arabs. In the late 8th century, the collapse of the Gokturk Khaganate led the Magyars and the Pechenegs, Ugric and Turkic peoples from Central Asia, to migrate west into the steppe region, leading to military conflict, disruption of trade, and instability within the Khazar Khaganate. The Rus' and Slavs had earlier allied with the Khazars against Arab raids on the Caucasus, but they increasingly worked against them to secure control of the trade routes.
Is there an answer to this question: Which area did the Khazars relinquish?

Answer: unanswerable

Question: Niels Bohr introduced the first quantized model of the atom in 1913, in an attempt to overcome a major shortcoming of Rutherford's classical model. In classical electrodynamics, a charge moving in a circle should radiate electromagnetic radiation. If that charge were to be an electron orbiting a nucleus, the radiation would cause it to lose energy and spiral down into the nucleus. Bohr solved this paradox with explicit reference to Planck's work: an electron in a Bohr atom could only have certain defined energies En
Is there an answer to this question: When was the last quantized model of the molecule introduced?

Answer: unanswerable

Question: Any philosophy that assigns crucial importance to the ideal or spiritual realm in its account of human existence may be termed "idealist". Metaphysical idealism is an ontological doctrine that holds that reality itself is incorporeal or experiential at its core. Beyond this, idealists disagree on which aspects of the mental are more basic. Platonic idealism affirms that abstractions are more basic to reality than the things we perceive, while subjective idealists and phenomenalists tend to privilege sensory experience over abstract reasoning. Epistemological idealism is the view that reality can only be known through ideas, that only psychological experience can be apprehended by the mind.
Is there an answer to this question: What view believes ideas are irrelevant to the real world?

Answer: unanswerable

Question: Much of Tucson's economic development has been centered on the development of the University of Arizona, which is currently the second largest employer in the city. Davis-Monthan Air Force Base, located on the southeastern edge of the city, also provides many jobs for Tucson residents. Its presence, as well as the presence of the US Army Intelligence Center (Fort Huachuca, the largest employer in the region in nearby Sierra Vista), has led to the development of a significant number of high-tech industries, including government contractors, in the area. The city of Tucson is also a major hub for the Union Pacific Railroad's Sunset Route that links the Los Angeles ports with the South/Southeast regions of the country.
Is there an answer to this question: What is the second-largest employer in Tucson?

Answer:
University of Arizona