In an undisturbed sequence of sedimentary rocks, younger layers overlay older layers, according to the principle of
a. superposition
b. original continuity
c. original horizontality
d. uniformitarianism

Correct option is part 'a' superposition.

Explanation:

Sedimentary rocks are formed when sediments are compressed under their own weight for a large period of time. Hence the layers that settle initially become the bottom layer's and hence are older than the layer's that are on the top.

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answer: a federal government has final authority on interstate/inter provincial  and international affairs, a confederation is one where the central/national government or authority is governing body what does not have final say over the same matters. hopefully this and i will try again if you don't like this answer : )

best of luck!

the first question's answer is a.