Answer:
refrain from using or disposing of (something); retain for future use.
Explanation:
An amino acid is the building block (or monomer) of proteins :)
Answer:
vitamin D ,........................
There is no picture shown, however details like this indicate that Scientist are examining the future changes in biodiversity within the Hudson river. If vegetation would see a continuous decrease, animals are forced to flee their habitat and find new areas or locations where they could thrive. When this happens, changes in the environment would put a great deal on the existence of certain forms of species within the area.