Question: Hunting and gathering was humanity's first and most successful adaptation, occupying at least 90 percent of human history. Following the invention of agriculture, hunter-gatherers have been displaced or conquered by farming or pastoralist groups in most parts of the world.
Is there an answer to this question: Which group has been displaced or conquered by farming?

Answer: unanswerable

Question: Sapwood (or alburnum) is the younger, outermost wood; in the growing tree it is living wood, and its principal functions are to conduct water from the roots to the leaves and to store up and give back according to the season the reserves prepared in the leaves. However, by the time they become competent to conduct water, all xylem tracheids and vessels have lost their cytoplasm and the cells are therefore functionally dead. All wood in a tree is first formed as sapwood. The more leaves a tree bears and the more vigorous its growth, the larger the volume of sapwood required. Hence trees making rapid growth in the open have thicker sapwood for their size than trees of the same species growing in dense forests. Sometimes trees (of species that do form heartwood) grown in the open may become of considerable size, 30 cm or more in diameter, before any heartwood begins to form, for example, in second-growth hickory, or open-grown pines.
Is there an answer to this question: What term is interchangeable with "sapwood"?

Answer: alburnum

Question: The primary circadian "clock" in mammals is located in the suprachiasmatic nucleus (or nuclei) (SCN), a pair of distinct groups of cells located in the hypothalamus. Destruction of the SCN results in the complete absence of a regular sleepwake rhythm. The SCN receives information about illumination through the eyes. The retina of the eye contains "classical" photoreceptors ("rods" and "cones"), which are used for conventional vision. But the retina also contains specialized ganglion cells that are directly photosensitive, and project directly to the SCN, where they help in the entrainment (synchronization) of this master circadian clock.
Is there an answer to this question: What would the loss of the SCN cells cause in the sleep-wake rhythm?

Answer: complete absence

Question: In June 1963, Rev. Martin Luther King, Jr. gave a major speech in Detroit that foreshadowed his "I Have a Dream" speech in Washington, D.C. two months later. While the African-American Civil Rights Movement gained significant federal civil rights laws in 1964 and 1965, longstanding inequities resulted in confrontations between the police and inner city black youth wanting change. Longstanding tensions in Detroit culminated in the Twelfth Street riot in July 1967. Governor George W. Romney ordered the Michigan National Guard into Detroit, and President Johnson sent in U.S. Army troops. The result was 43 dead, 467 injured, over 7,200 arrests, and more than 2,000 buildings destroyed, mostly in black residential and business areas. Thousands of small businesses closed permanently or relocated to safer neighborhoods. The affected district lay in ruins for decades. It was the most costly riot in the United States.
Is there an answer to this question: Who was the President of the United States in 1967?

Answer:
President Johnson