Answer:
Spiral Galaxies, Elliptical Galaxies & Irregular Galaxies
Explanation:
How did galaxies originate? Astronomers believe that after the big bang, the explosion which began the universe 10 billion to 20 billion years ago, gravity began to compress masses of free-floating gas. Two main theories, bottom-up and top-down, explain what happened next. According to bottom-up theories, clusters began to form and assembled together into the larger units we know as galaxies. Top-down theories suggest that galaxies formed first, and the stars and other objects within them were subsequently produced. They categorized different galaxies to maintain their tests from the other galaxies.
Natural selection is the differential survival and reproduction of individuals due to differences in phenotype.
Every time I see natural selection, I hear The Horrible Histories song.https://www.youtube.com/watch?v=aZETITM2IPg
<span>A SCIENTIFIC HYPOTHESIS is a possible and testable answer to a scientific question or explanation of what scientists observe in nature. It is the initial building block of a scientific method, and also includes an explanation, for the assumption that the hypothesis is correct.</span>
Answer:B. All of the above
Explanation: Fossil fuels do generate electricity. Example burning coal
Acid rain is cause by Sulfur dioxide. Sulfur dioxide is produced from powerplants.
When you burn Fossil fuels it increases the atmospheric Co2.
The continental crust is made mostly of rocks. Both oceanic crust and continental crust are less dense than the mantle, but oceanic crust is denser than continental crust. The mantle, oceanic crust and continental crust have different densities because they are made of different kinds of rock with different densities.<span> the oceanic crust is made mostly of rocks with a composition of basalt.</span>
