Because though there is a lot of available water, an ever shrinking 3% is freshwater, which comes from groundwater and streams. The ocean is salinated and in order for it to be fit to be used by humans for domestic needs or for drinking, it needs to undergo a huge desalination process which costs lots of money and time.
Answer:
The weather change as the earth warms because since,20th century due to human activities, particularly fossil-fuel burning which increases heat- trapping greenhouse gas levels in Earth's atmosphere.
It’s the first one for sure
they are layered mounds of deposits made by precambrian algae
