Answer:
The correct option is A. they evolved from land mammals.
Explanation:
Evolution can be described as a process through which organisms in a species change over a period of time due to the natural selection of the environment. Those organisms that have many similarities in their functions or structures are considered closer to one another and have the same common ancestors.
The properties mentioned in the question about cetaceans resembles the properties of land mammals. For example, cetaceans lack gills and breathe air. Land mammals also do not have gills and need to respire for living. The cetaceans have fin bones which are similar to the limb bones in the land mammals. Hence, these observations show that cetaceas have evolved from land mammals.
Coal, oil, and, natural gas
Answer:
C. Only bacteria can reproduce outside a host.
The practice of leaving crop residues on the field in between planting seasons is known as conservation tillage.
<h3>Conservation tillage</h3>
Some soils are prone to erosion once they are directly exposed to the impact of precipitation.
After harvesting crops from a field, the crop residues are left on the field to prevent the direct impact of precipitation in cause erosion. The crop residue, in addition, adds to the organic matter of the soil after their decomposition.
Such a practice is known as conservation tillage.
More on conservation tillage can be found here: brainly.com/question/14575699
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Answer:
sure
but what is that u need help with
Explanation:
