Which describes best how charles darwin provided evidence that evolution occurs?

a. he sailed around the world on the beagle making observations.

b. he used dna to show where adaptations come from.

c. he compared two groups of finches to illustrate natural selection.

d. he bred turtles to show their adaptations.

the correct answer: the index of refraction of the second medium is lower i tried this persons answer and it was wrong this person is lying

igneous rocks are formed by solidification of cooled magma (molten rock), with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks.  

the composition depends on the source magma. there are almost a thousand types of composition found till now.  

hope this