Only the federal government regulates interstate trade
Option D.
<u>Explanation:</u>
The federal government is the central government in the United States of America which is linked with the welfare of the whole country and the state government is linked with the welfare of the people of a particular state only in the country.
Because of the difference in the aims of the two types of the country, the delegation of powers is also different between these types of the government. one of the powers which rests with the central but not with the state government s the regulation of the inter state trade.
Let's start from the beginning.
<span>Millions and millions of years ago, planet Earth was absolutely crowded with volcanoes. </span>
<span>As you may know, volcanoes release steam and gasses. </span>
<span>As the years went by, the gasses released from volcanoes formed the atmosphere around the planet, which prevented the steam from disappearing into outer space. </span>
<span>The steam eventually, in cycles, began to fall back to Earth. Viola, rain had just been "invented". </span>
<span>As more and more rain fell, considering almost every surface of the planet was volcanic, the water began to build up and "flood" the planet. Many active volcanoes had now been transformed into underwater volcanoes. </span>
<span>As more and more years went by, eventually, bacteria in the water slowly began to evolve, first into jelly-fish like creatures, then tadpole-like creatures, leading all the way up to large ferocious underwater reptiles, amphibians and fish. </span>
<span>As the planet started to warm up, probably by methane gasses released from the prehistoric underwater creatures, the water levels on Earth began to drop again. At the same time, the active underwater volcanoes were creating new landmasses, either by lava cooling on the surface of the water or tectonic plates pushing the volcano above sea level. </span>
<span>So, this, is how fossils of sea creatures ended up in high land-based mountains. </span>
<span>Because millions of years ago, most of Earth was underwater until the water levels dropped or lands "grew" higher. </span>
<span>The Rocky Mountains were once underwater. </span>
<span>If you take a look at images of the Grand Canyon in the United States, you'll see that it resembles the deep caverns and canyons that you find at the bottom of oceans. </span>
<span>That's because the Grand Canyon WAS at the bottom of an ocean.</span>
Answer:
Groundwater flows from areas with a higher water table surface to areas with a lower water table. This mixture of carbonic acid in water makes most natural surface waters slightly acidic. As slightly acidic water infiltrates the ground to become part of the groundwater system it causes weathering of the rocks.
<em>Hope that helps! :)</em>
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<em>-Aphrodite</em>
Explanation:
Answer:
<em>The correct option is theories. </em>
Explanation:
A scientific theory is a detailed explanation of natural researches which are supported through evidence. Scientific theories can be changed if other evidence are made which support another theory. Hence, scientific theories can change. The concepts of plate tectonics and evolution change overtime whenever new pieces of evidence are discovered. Hence, they are scientific theories.
Other options such as hypotheses are not correct because a hypothesis is just a tentative statement which can either be proved to be correct or wrong. Observations are not made on evidences hence the option observations is also not correct.
