Problem: Mechanical pulping yields almost a tonne of pulp per tonne of dry wood used, which is why mechanical pulps are sometimes referred to as "high yield" pulps. With almost twice the yield as chemical pulping, mechanical pulps is often cheaper. Mass-market paperback books and newspapers tend to use mechanical papers. Book publishers tend to use acid-free paper, made from fully bleached chemical pulps for hardback and trade paperback books.
What level of acid is not usually found in the paper used by book publishers?
---
Answer: unanswerable


Problem: Carpet-weaving is historically a major traditional profession for the majority of Armenian women, including many Armenian families. Prominent Karabakh carpet weavers there were men too. The oldest extant Armenian carpet from the region, referred to as Artsakh (see also Karabakh carpet) during the medieval era, is from the village of Banants (near Gandzak) and dates to the early 13th century. The first time that the Armenian word for carpet, gorg, was used in historical sources was in a 1242–1243 Armenian inscription on the wall of the Kaptavan Church in Artsakh.
What is the Armenian word for weaving?
---
Answer: unanswerable


Problem: During the early years of the Cold War from 1946 to 1958, the United States tested 67 nuclear weapons at its Pacific Proving Grounds located in the Marshall Islands, including the largest atmospheric nuclear test ever conducted by the U.S., code named Castle Bravo. "The bombs had a total yield of 108,496 kilotons, over 7,200 times more powerful than the atomic weapons used during World War II." With the 1952 test of the first U.S. hydrogen bomb, code named "Ivy Mike," the island of Elugelab in the Enewetak atoll was destroyed. In 1956, the United States Atomic Energy Commission regarded the Marshall Islands as "by far the most contaminated place in the world."
In what year did the Cold War begin?
---
Answer:
1946