The Precambrian time refers to the time 4.5 billion to 542 millions year ago. This period is characterized by having reduced atmosphere and included reduced compounds. Scientists believed that atmosphere at that time was devoid of free oxygen and CO2 was present in excess. Before the complex life evolved on the Earth, the Precambrian Earth's ocean contained dissolved carbon dioxide.
Answer:
1) sound is encoded on a digital recording as an electrical signal.
2) the digital recording plays the sound as an electrical signal.
3) the electric signal moves through a voice coil
4) The voice coil produces a magnetic field.
5) changing the magnetic field pushes and pulls on the diaphragm.
Answer:
Passing through clay beds filters groundwater, purifying out soil, or organic materials, and contaminants to leave behind pure water that fills up aquifers.
Explanation:
I hope this help you .
Answer:
B: The shorter and more rounded the Appalachian Mountains are more than four times older than the taller and more jagged Rocky Mountains
Explanation:
- The Appalachian mountains form a system of mountains in eastern North America and are older than rocky mountains as they were formed 480 million years ago and are similar to those of the alps. They form a barrier to the east to the west.
- They extend to southeast Canada and form zones of 300 miles wide. They form the mountain ranges surrounding hills and the dissected plateaus forming at an elevation of 6,684 meters from the sea level. <u>Whereas the rocky mountains are younger and have an elevation of 4,401 meters.</u>
