Answer:
(a) Ecosystem, community, population, individual
is right answer I think
<span>The youngest rock layers are at the top and the oldest are at the bottom, which is described by the law of superposition.</span><span>Fossil layers are fossils that formed in sedimentary rock. Sedimentary rock is rock that is formed in layers by the depositing and pressing of sediments on top of each other. </span>
Petroleum is the primary fuel used for transportation in the US because it has a high energy value per unit volume and it has a quick start and stop times for providing energy. Additionally, petroleum is extremely easy to extract, it is a high density fuel, can also be transported over long distances and provides fuel that works with our infrastructure.