Answer: Paleozoic
Explanation: The Paleozoic Era, which ran from about 542 million years ago to 251 million years ago, was a time of great change on Earth. The era began with the breakup of one supercontinent and the formation of another plants became widespread. And the first vertebrate animals colonized land.
Answer:
d. cells
cardiac tissue are made up of cells.
Answer:
the answer is always wear safety goggles