Answer - The geography of India greatly influenced the location of early settlements on the subcontinent. Both the Indus and the Ganges rivers carried rich silt from the mountains to the plains. When the rivers flooded, the silt spread over the plains and made the soil in the river valleys fertile for farming.
In an experiment, you used a solvent to extract fat from hamburger meat. When you are finished in the experiment, then you should put the solvent and the fat into waste containers that are specific for the solvent used in the experiment. You cannot just throw them into the sink as it may pollute and cause unwanted effect on bodies of water. Also, you cannot throw it together with other wastes as you do not know the reaction that would happen with it with the other wastes.
