Explanation:
To swim, they move their tails up and down, rather than back and forth as fishes do. This is because whales evolved from walking land mammals whose backbones did not naturally bend side to side, but up and down. ... Whales do the same thing as they swim, showing their ancient terrestrial heritage.
Cetaceans are fully aquatic marine mammals belonging to the order Artiodactyla, and branched off from other artiodactyls around 50 mya (million years ago). Cetaceans are thought to have evolved during the Eocene or earlier, sharing a closest common ancestor with hippopotamuses.
Answer:its " with monitoring, the concentration of every pollutant has decreased."
Explanation: just took it on Ap3x
I am going to have to say algae and fungus.
Hope this helps, if not, comment below please!!!
They cant be faster because they have smaller fins but thats just my logic hope i helped
