There are only two extinct groups of cetaceans: Rodhocetus and Dorudon. True or False Rodhocetus went extinct approximately 40 million years ago. True or False
All the branches that extend to zero on the timeline represent animal groups living today. True or False
Living cetaceans share a more recent common ancestor with hippopotamuses than with extinct cetaceans.
Cetaceans evolved before even-toed ungulates, such as deer and cows. True or False

bc blah

explanation:

bc blah

estuaries are the partially enclosed coastal bodies of brackish water formed at the mouth of sea where river meets an ocean. it is a transition zone between river and sea water so estuaries are influenced to both marine environment such as tides, waves and to riverine such as flow of fresh water and sediments. the mixing of sea and fresh water provide high level of nutrients, making estuaries a high product habitats.

many estuaries suffers degradation from a variety of human activities like erosion from deforestation, overgrazing, overfishing, drainage and eutrophication.

so from the above statement answers will be

1. false as estuaries are formed due to both brackish and freshwater.

2.true, due to high productivity estuaries are breeding ground for many marine species.

3. direct and indirect activities of man that contribute to pollution and deposition of sediments.