Why is earth considered an open system and a closed system?

The earth is a closed system because only energy is naturally transferred outside the atmosphere.

Explanation:

All systems inside the Earth, on the other hand, are open systems as both energy and matter can be transferred between the systems and their surroundings.

explanation:

the fossil record extends back to a dog-like ancestor some 55 million years ago, which gave rise to the first horse-like species 55 to 42 million years ago in the genus eohippus.

it would lead to upper respiratory infections and pneumonia.