Question: Bantu-speaking peoples who founded tribes during the Bantu expansions largely displaced and absorbed the earliest inhabitants of the region, the Pygmy people, about 1500 BC. The Bakongo, a Bantu ethnic group that also occupied parts of present-day Angola, Gabon, and Democratic Republic of the Congo, formed the basis for ethnic affinities and rivalries among those countries. Several Bantu kingdomsnotably those of the Kongo, the Loango, and the Tekebuilt trade links leading into the Congo River basin.
Is there an answer to this question: When did the Pygmy people displace the Bantu?

Answer: unanswerable

Question: Since at least the time of the Ancient Greeks, a proportion of Jews have assimilated into the wider non-Jewish society around them, by either choice or force, ceasing to practice Judaism and losing their Jewish identity. Assimilation took place in all areas, and during all time periods, with some Jewish communities, for example the Kaifeng Jews of China, disappearing entirely. The advent of the Jewish Enlightenment of the 18th century (see Haskalah) and the subsequent emancipation of the Jewish populations of Europe and America in the 19th century, accelerated the situation, encouraging Jews to increasingly participate in, and become part of, secular society. The result has been a growing trend of assimilation, as Jews marry non-Jewish spouses and stop participating in the Jewish community.
Is there an answer to this question: When did the advent of the Jewish Enlightenment occur?

Answer: 18th century

Question: During the English Civil War the majority of Londoners supported the Parliamentary cause. After an initial advance by the Royalists in 1642 culminating in the battles of Brentford and Turnham Green, London was surrounded by defensive perimeter wall known as the Lines of Communication. The lines were built by an up to 20,000 people, and were completed in under two months. The fortifications failed their only test when the New Model Army entered London in 1647, and they were levelled by Parliament the same year.
Is there an answer to this question: Approximately how many workers did it take to build the Lines of Communication?

Answer: 20,000

Question: Paper made from wood pulp is not necessarily less durable than a rag paper. The ageing behavior of a paper is determined by its manufacture, not the original source of the fibres. Furthermore, tests sponsored by the Library of Congress prove that all paper is at risk of acid decay, because cellulose itself produces formic, acetic, lactic and oxalic acids.
Is there an answer to this question: Besides formic, acetic, and lactic acid, what type of acid does cellulose produce?

Answer:
oxalic