Why are over one-sixth of the world's people at risk for running out of drinking water? (a) the oceans are drying up. (b) there is not enough surface water. (c) the world's fresh water wells are drying up. (d) glaciers in many areas are melting.

Your answer is d. silli hope this ! : ) i left an explanation down below if you need it: a sill forms when hot magma squeezes between layers of rock to form a hardened sheet of rock. a sill is basically a tabular sheet intrusion between old layers of sedimentary rock, volcanic beds, or in the direction of foliation inherent in metamorphic rock. the word sill means a concordant intrusive sheet.