Problem: Animals are also involved in the distribution of seeds. Fruit, which is formed by the enlargement of flower parts, is frequently a seed-dispersal tool that attracts animals to eat or otherwise disturb it, incidentally scattering the seeds it contains (see frugivory). Although many such mutualistic relationships remain too fragile to survive competition and to spread widely, flowering proved to be an unusually effective means of reproduction, spreading (whatever its origin) to become the dominant form of land plant life.
What did accidentally scattering seeds help flower parts evolve to form?
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Answer: unanswerable


Problem: It is generally considered that the Pacific War began on 7/8 December 1941, on which date Japan invaded Thailand and attacked the British possessions of Malaya, Singapore, and Hong Kong as well as the United States military bases in Hawaii, Wake Island, Guam and the Philippines. Some historians contend that the conflict in Asia can be dated back to 7 July 1937 with the beginning of the Second Sino-Japanese War between the Empire of Japan and the Republic of China, or possibly 19 September 1931, beginning with the Japanese invasion of Manchuria. However, it is more widely accepted that the Pacific War itself started in early December 1941, with the Sino-Japanese War then becoming part of it as a theater of the greater World War II.[nb 9]
When did Japan invade Manchuria?
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Answer: 19 September 1931


Problem: The lowest pressure that can be attained in a system is also dependent on many things other than the nature of the pumps. Multiple pumps may be connected in series, called stages, to achieve higher vacuums. The choice of seals, chamber geometry, materials, and pump-down procedures will all have an impact. Collectively, these are called vacuum technique. And sometimes, the final pressure is not the only relevant characteristic. Pumping systems differ in oil contamination, vibration, preferential pumping of certain gases, pump-down speeds, intermittent duty cycle, reliability, or tolerance to high leakage rates.
How do leakage rates usually happen?
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Answer:
unanswerable