Answer:
4.5 billion years ago
Earth hasn't always been a blue and green oasis of life in an otherwise inhospitable solar system. During our planet's first 50 million years, around 4.5 billion years ago, its surface was a hellscape of magma oceans, bubbling and belching with heat from Earth's interior.
Explanation:
Answer:
A .They result in sudden gene frequency changes.
Explanation:
Answer:
When a cold front overtakes a warm front, it creates what's called an occluded front that forces warm air above a frontal boundary of cooler air masses.
Explanation:
The presence of a cold front means that cold air is advancing and pushing underneath warmer air. This is because the cold air is ‘heavier,’ or denser, than the warm air. Cold air is thus replacing warm air at the surface.
