Most dissolved carbon in the ocean is used to form which structure in marine organisms?

The diagram below shows the layers of a rock having a trilobite: a rock column labeled rock is shown. the column has three layers. the bottommost layer of the rock has one shaded rhomboid shape, the middle layer has a rhombus with a diagonal along with two identical organisms marked as, trilobite, in the key, the top layer has two semicircles. a key is shown on the right side of the diagram. the shaded rhombus is marked as a, the rhombus with the diagonal is marked as b, the semicircle is marked as c which statement about the rock fossils is true?

Can nonrenewable resources be used sustainably?

If we assume that, in the african savanna, rainfall and the amount of grass is plentiful, what other factor would best explain a reduced antelope population?