About 4,000 new species of marine animals were discovered in the last 2 years. What is the unit rate of
discovery? (1 point)
4,000 species
2 years
2 years
4,000 species
1 species
2,000 years
2,000 species
year
discovery? (1 point)
4,000 species
2 years
2 years
4,000 species
1 species
2,000 years
2,000 species
year