During superposition of a wave such as that of the oceans, when the crest and the trough meet, then they cancel out into the period. If two crests meet up, they add up to a crest that’s equivalent to the summation of their amplitudes. This is also true when two troughs meet up.
Why is the pulmonary circulation reduced in the human fetus? Pulmonary circulation is reduced in the human fetus because the baby gets its oxygen from its mother and does not breath on its own.
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Human impact on coral reefs is significant. ... Damaging activities include coral mining, pollution (organic and non-organic), overfishing, blast fishing, the digging of canals and access into islands and bays. Other dangers include disease, destructive fishing practices and warming oceans.Factors that affect coral reefs include the ocean's role as a carbon dioxide sink, atmospheric changes, ultraviolet light, ocean acidification, viruses, impacts of dust storms carrying agents to far-flung reefs, pollutants, algal blooms and others. Reefs are threatened well beyond coastal areas. Climate change, such as warming temperatures, causes coral bleaching, which if severe kills the coral.
In 2008, a worldwide study estimated that 19% of the existing area of coral reefs has already been lost, and that a further 17% is likely to be lost over the subsequent 10–20 years.[3] Only 46% of the world's reefs could be currently regarded as in good health [3] and about 60% of the world's reefs may be at risk due to destructive, human-related activities. The threat to the health of reefs is particularly strong in Southeast Asia, where 80% of reefs are endangered. By the 2030s, 90% of reefs are expected to be at risk from both human activities and climate change; by 2050, it is predicted that all coral reefs will be in danger.
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true or so google says lol