Question

use the drop - down menus to complete the statements. choose... rocks are the most useful for scientists in determining the history of earth because they contain fossils. this information, combined with the choose... , allows scientists to determine the relative ages of rock layers.

Explanation:

The first blank refers to sedimentary rocks, as they are the primary rock type that preserves fossils and is key for relative dating of Earth's history. The second blank is the law of superposition (or principle of superposition), the fundamental geological principle that states in undisturbed rock layers, older layers are below younger ones, which when combined with fossil data, lets scientists determine relative rock layer ages.

Answer:

1. First dropdown: sedimentary rocks
2. Second dropdown: principle of superposition