Fossils questions.. plz help .. thanks :)?

Question

1. The first fossils of living things date back about ---- years ago
a. 2 500 000 000
b. 3 500 000 000
c. 100 000 000
d. 100 000

2. Animal species first appeared during the
a. Paleozoic Era
b. Cenozoic Era
b. Proterozoic Era
c. Mesozoic Era

Answer 1

The first fossil single-celled organisms appear b. 3,500,000,000 years ago.

Animals, which are multicellular, appeared in the Proterozoic (note that your 2nd question has 2 "b's").

Answer 2

1) C
2) Proterozoic

Double check these