It is water pollution, since you are polluting the river.
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Answer:
Polygenic trait
Explanation:
A polygenic trait is a type of trait whose phenotype observed is affected by more than one genes i.e expression of the trait is controlled by not only a single gene but many. These traits include height or skin color and they display that display a continuous distribution; the hair color is controlled by 7 genes as described which is more than more.
Answer:
C. 1.23 g/ml
Explanation:

Mass of rock = 80g
Volume of rock = final fluid volume - initial fluid volume
Volume of rock = 265 cm³ - 200 cm³ = 65 cm³


1 cm³ = 1 ml
Therefore, density of the object = 1.23 g/ml