Gun powder was used for military purposes in the 919 A.D. It killed many people in China. It was explosive.
Answer:
the amount of water vapor in the air
Explanation:
That's the amount of water vapor in the air that represents BEST the definition of humidity and what causes our sensation of the temperature to vary based on it.
That's why wet tropical forests are much more humid than arid dry deserts.
The other sentences are expressions of phenomenons that take place at various humidity levels, in various circumstances. When the humidity is very high, it will most likely cause storms and rain will fall.
Answer: He was referring to the production technologies i.e. the methods employed to extract, produce and utilize resources were man-made and far from naturally ideal.
Explanation: Barry Commoner was an American cellular biologist, professor and politician. He was a leading ecologist and among the founders of the modern environmental awareness movements.
The above excerpt is from his book, The Closing Circle published in 1971, where Commoner exposed the role of capitalism and profit as root causes of environmental degradation, at a time when majority of writers were blaming individual behaviour or overpopulation for pollution.
C. The gate-control theory. The gate control theory of pain states that non-painful inputs closes the nerve gates to painful input, which prevents pain sensation from traveling to the central nervous system.
