Question

21. When did the Precambrian era end?

approximately 5.4 million years ago
approximately 2 million years ago
approximately 100,000 years ago
approximately 540 million years ago

Answer 1

Answer: approximately 540 million years ago

Step-by-step explanation:

Answer 2

Answer: The Precambrian era ends abot 540 million years ago.

Step-by-step explanation:

The Precambrian era is the first geologic era of the Earth, it initiates from the Earth's formation (4600 million years ago) and ends at the beginning of the Cambrian era (541 million years ago). It is the longest geologic era of the Earth.