Answer: SUBSTANCES CAN ALSO BE ELEMENTS
Explanation:
I'M SMART
The reason is that something changed that caused them to be unsuccessful in their environment.
Sorry if it is not right.
Am certain that the factor that prevents us from finding fossils from the Precambian era is that Most rocks from that era are deeply buried. The precambrian is the informal name for the large expanse of time preceding the current Phanerozoic Eon. It began with the Earh's Formation about 4.5 billion years ago and lasted until the advent of multicellular life about 542 million years ago.
Process A likely describes a photosynthesis whilst process B describes respiration.
