Answer:
during the Cambrian Period of the Paleozoic Era.
Explanation:
The Paleozoic is the earliest era (of three) of the Phanerozoic Eon and is composed of six geologic periods: the Cambrian, Ordovician, Silurian, Devonian, Carboniferous, and Permian (in that order from earliest to the latest). Fish first appeared about 530 million years ago during the Cambrian explosion.
Your answer for this question is paper which Is A
Answer:
B) Help produce oxygen
C) Help make foods
D) Help break down dead materials
Explanation:
B - Life on Earth <em>depends</em> on protists since they are the ones who supply us with oxygen.
C - Provide food to other living organisms in food chains/webs.
D - Even, recycle important nutrients just for other life forms to use (some protists may also be decomposers; as they also release nutrients into the environment).
This is a false statement