Acid rain occurs when sulfur dioxide in the atmosphere is oxidized in the presence of nitrogen dioxide. acod rain is and example of

Acid rain is a type of precipitation with acidic components which is harmful to the environment, plants, animal and human beings.  There are not only natural sources that produce gases to the atmosphere like, volcanoes, but also the intense human activity that released a great amount of chemicals into the air. Some examples of this are: means of transport, power plants, electricity generation and factories.

1. between 1754 and 1763

2. a land bridge between siberia and alaska that was exposed during the most recent ice age when the waters of the bering strait receded.

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