Did dinosaurs exist in the pre-cambrian period?

Which set of characteristics best describes sedimentary rock? a) largest type of rock, made of organic matter, hardest type of rock b) often contains layers, forms near sources of water, contains fossils c) least abundant type of rock, made of other rocks, made mostly of minerals d) most abundant type in earth's crust, made of magma/lava, contains no fossils

Explain how scientists use geologic time to determine the age of landforms.

Which macromolecule catalyzes chemical reactions this be considered enzyme chemical reactions thus he considering enzymes