Pollution Pollution is the introduction of contaminants into a natural environment that causes instability, disorder, harm or discomfort to the ecosystem i.e. physical systems or living organisms. Pollution, contamination of Earth’s environment with materials that […]
PathshalaNepal.com is a Registered Company of E. Pathshala Pvt Ltd Nepal. Registration number : 289280
© 2020. All right Reversed.E. Pathshala Pvt Ltd