The first hispanic heritage was celebrated in the united states in the year 1968
There are three kinds of rock: igneous, sedimentary, and metamorphic. Igneous rocks form when molten rock (magma or lava) cools and solidifies. Sedimentary rocks originate when particles settle out of water or air, or by precipitation of minerals from water.
It created jobs for the US and increased employment and incomes as well and also lowered prices
The correct answer is D. ocean floor mapping and earthquake tracking
Tracking earthquakes is helpful because it shows where it came from and what caused it, as well as how it affected the environment, while ocean floor mapping is useful because it shows how the bottom of the sea changed over time which happens due to tectonic activity.