Igneous rock derives it's name from the Latin word ignis which means fire. It is formed when the magma after volcanic eruption gets cool and solidified either on the surface of earth crust or inside the earth crust. These rocks are characterized by their hardness. These rocks undergoes no chemical weathering but exhibit very low mechanical or physical weathering may occur. Therefore, hardness is the property which can be used to identify the origin of an igneous rock.
Answer:
A political system for choosing.
Explanation:
Answer:
1. giant impact forms moon
2. end of heavy bombardment
3. early life (based on fossil evidence))
4. oxygen buildup in atmosphere
5. earliest mammals
6. dinosaurs go extinct
7. earliest humans
Explanation:
The Earth has a very interesting past, with lot of changes and turnarounds in it. If we sum it up quickly, we can say that soon after the Earth formed and collided with another large space object, part of the Earth was torn away, which eventually formed the moon. The Earth was constantly bombarded by meteorites and asteroids, but that came to an end as the atmosphere was becoming denser and denser. The first life started to develop in the oceans in the form of cyanobacteria, which used photosynthesis, and were constantly releasing oxygen, building it up int he atmosphere. The oxygen changed the living conditions, enabling the life to thrive and diversify. The dinosaurs and mammals eventually came on the scene, with the dinosaurs coming first by around 20 million years, giving them the edge to become the dominant life form. The mammals lived in the shadows until the dinosaurs existed, but their reign ended with a large meteorite collision. This prompted the quick evolution and diversification of the mammals, quickly becoming the dominant life form, and just few million years ago they gave rise to the earliest human ancestors, the hominids.
<u>Answer</u>: Fish A because of its elongated body and powerful tail.
<u>Explanation</u>: An elongated body gives the fish a streamlined or fusiform shape. This enables them to slide more esily through water, thus decreasing the energy expenditure of the fish for swimming. Powerfull tails also enables them to swim over long distances as well as bursts of speed. This speed capability is vital when the fish will either try to avoid a predator or, if it is a predator itself, catch its prey.
