By using the method of we can know how much of each element is in a star because the chemical elements present in the atmosphere of the star create absorption
lines.

Answer the use of flood plains and irrigation;

Ibelieve the answer is c. map projections.hope my answer has you : )

How is this even a question?

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.