Answer:
a) Mixes the entire oceans every 1.5 million years.
Explanation:
The 11th century was when Caliphs brought Islam to India.
<span>military overreach and political incompetence.</span>
Answer:
Some technological choices may have been less successful. Examples are lead pipes, used in the antique and continues to be used in house connections. until recently water and sanitation systems are at need of constant maintenance and rehabilitation. which was already seen in Roman aqueducts. such as calcium carbonate incrustations formed inside, and without constant removal it will stop the water flow. the same as for modern systems they need to be taken care of or else they will not function properly. that is the bigger problem the constant replacement and fixing. A long term debatable issue is what source to use and whether to use ground or surface water. surface water is needed for bigger systems, and smaller systems usually use ground water. this is the current question how far is it economically possible to expand the systems. once these systems are expanded the only thing wrong is being over exposed.
Explanation:
