Between the time period of dinosaurs in the Cretaceous Period of the fossil record to the time of the first human fossil record in the Pleistocene Era was _75 million years years.

A. 75 million years

B. 35 million years

C. 66 million years

D. 750 thousand years

What is the following best defines climate?

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

When you run, you begin to breathe heavier and faster. your heart beats more quickly, bringing more oxygen to your cells. which organ systems are working together here?