The significance of the yearly flooding of the Nile Valley is important because it replenishes nutrients in the soil and makes the land more fertile for plants to grow.
A primary pollutant is an air pollutant emitted directly from a source.
A secondary pollutant is not directly emitted as such, but forms when other pollutants (primary pollutants) react in the atmosphere.
Examples of a secondary pollutant include ozone, which is formed when hydrocarbons (HC) and nitrogen oxides (NOx) combine in the presence of sunlight; NO2, which is formed as NO combines with oxygen in the air; and <em><u>acid rain</u></em>, which is formed when sulfur dioxide or nitrogen oxides react with water.
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Explanation:
The shape may have been developed to represent the longevity of a relationship, but it's valued because the oval diamond can make one's fingers look longer and thinner.
<span>Britain......................................</span>