D.
When one population cannot interbreed with the other population. FUN FACT! There's an exception. If a Lion has sex with a Tiger, a rare unfertile species called a 'Liger' is produced.
Everyone makes mistakes because no is perfect. No one can be perfect no matter how hard they try. Not even that beautiful, young woman. She has her own flaws just like everybody else. So stop asking why do you make mistakes, and start asking how can I learn and grow from your mistakes. If someone doesn't like you for you, thats an issue they have to deal with. It's not your responsibility to change people. Instead move on and find someone better. Someone who will recognize your mistakes as your greatness.
Explanation:
Given the importance of oxygen for animals, researchers suspected that a sudden increase in the gas to near-modern levels in the ocean could have spurred the Cambrian explosion. ... This supported the idea of oxygen as a key trigger for the evolutionary explosion.
Oceanic Crust
Continental Crust
Oceanic crust is denser than continental, this is why continents are at higher elevation than oceans.
<h2>
Answer: It is the same force that causes an apple to fall to the ground.</h2>
The force that makes two galaxies to be attracted to each other is the same force that causes an apple to fall to the ground. This is known as the Gravity Force.
This force was named by Issac Newton, after some empirical observations in nature and then he published the Universal Law of Gravitation on 1687:
<em>The force 
exerted between two bodies of masses 
and 
and separated by a distance 
is equal to the product of their masses and inversely proportional to the square of the distance.</em>
Written in a mathematical form is:
Where 
is the gravitational constant
So, this force between two bodies (two galaxies or an apple and the ground) is directly proportional to the product of the mass of both and inversely proportional to the square of the distance that separates both bodies.
This means the gravity force <u>decreases</u> when the distance between these two bodies <u>increases</u>.
Therefore, the correct option is a.
