15. The human embryo and all other vertebrate embryos have gill slits. This best supports the idea that a. Life descended from water
b. Embryos can breathe under water
c. Vertebrates are evolutionarily related
d. Humans become fish before they become human

Hurry which of these is true about index fossils? a) are very scarcely found b) used as guides in relative dating c) found in the youngest layer of the rock d) used as reference points in absolute dating

What best describes the structure of the declaration of independence?

Why is earth's outer core hotter than earth’s oceanic crust? earth’s oceanic crust is denser than earth’s outer core is. earth’s oceanic crust has lava flowing from the mantle. earth’s outer core has a composition of solid iron and nickel. earth’s outer core is deeper within earth than oceanic crust is.