Leukocytes are produced/stored in thymus, spleen, and bone marrow
Pollution can come from both natural sources and human activities depending on the type of pollutant.
<h3>What is pollution?</h3>
It is the release of substances into the environment to the extent that the well-being of plants, animals, and humans starts getting affected.
Substances that are released into the environment to the extent that they start affecting the organisms in the environment negatively are known as pollutants.
Pollutants can come from natural sources or as a result of human activities.
For example pollutants such as oxides of sulfur, methane, carbon dioxide, etc. can come from natural processes such as volcanic eruptions, activities of microbes, etc.
Pollutants such as oxides of carbon and sulfur can also be generated as a result of human activities such as the burning of coal, technological inventions, etc.
More on pollution can be found here: brainly.com/question/23857736
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I think it is the second answer, sorry if it is wrong/didn’t help.
DnaG
That’s the first answer that came up on google
