When did the united states enter world war i? what was the significance of
the entry of the u. s. into the war?

Under president reagan, the united states began to develop the strategic defense initiative, nicknamed "star wars.” what was the goal of that plan?

The largest formal unit of geologic time is

Nwhich situations is the principle of cross-cutting relationships useful in determining relative age? check all that apply. a fault breaks through sedimentary layers. sedimentary layers form and then are tilted. igneous rock forms between sedimentary layers. sedimentary layers form over millions of years in a lake bottom. lava flows form on top of one another from several eruptions over time.