D. Some European rivers act as international borders.
Answer:
This region was formed when cracks in the Earth's crust created a rift valley, which is a “valley created when the part of land between the cracks in the Earth's crust drops down”. Two major waterways that are located within this landform region are the St. Lawrence River and Lake Huron.
Explanation:
It is considered one region!
Answer:
4 billion years
Explanation:
Scientists have found the oldest known rocks on Earth. They are 4.28 billion years old, making them 250 million years more ancient than any previously discovered rocks. Earth formed about 4.6 billion years ago from a disk of gas and dust circling the sun.
