Network hardware, software and specifications, as well as the expertise of network management personnel are important in ensuring that data follows the most efficient route, and upstream connections work reliably. A tradeoff between cost and efficiency is possible.[citation needed]
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): What ensures upstream connections are not reliable?
Ah, so.. unanswerable

Time is one of the seven fundamental physical quantities in both the International System of Units and International System of Quantities. Time is used to define other quantitiessuch as velocityso defining time in terms of such quantities would result in circularity of definition. An operational definition of time, wherein one says that observing a certain number of repetitions of one or another standard cyclical event (such as the passage of a free-swinging pendulum) constitutes one standard unit such as the second, is highly useful in the conduct of both advanced experiments and everyday affairs of life. The operational definition leaves aside the question whether there is something called time, apart from the counting activity just mentioned, that flows and that can be measured. Investigations of a single continuum called spacetime bring questions about space into questions about time, questions that have their roots in the works of early students of natural philosophy.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): In what two systems is philosophy considered a fundamental physical quantity?
Ah, so.. unanswerable

Starting at the transition between the Middle to Upper Paleolithic period, some 80,000 to 70,000 years ago, some hunter-gatherers bands began to specialize, concentrating on hunting a smaller selection of (often larger) game and gathering a smaller selection of food. This specialization of work also involved creating specialized tools, like fishing nets and hooks and bone harpoons. The transition into the subsequent Neolithic period is chiefly defined by the unprecedented development of nascent agricultural practices. Agriculture originated and spread in several different areas including the Middle East, Asia, Mesoamerica, and the Andes beginning as early as 12,000 years ago.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): In what period did all hunter-gatherers begin to specialize?
Ah, so..
unanswerable