B. is a protective structure made of cellulose fibrils
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You absorb vitamin d from sunlight shining on your skin.
Vitamin d can help the absorption of calcium, which is capable for strengthening your bones and teeth.
Therefore if u r lacking of vitamin d, your bones and teeth may be soft, and especially among children, you may get ricket, where the legs are bent outwards.
Answer:
It's an alarming situation about the decline of commercial fish population and we must need to develop the policy solution to this dangerous fisheries problem.
We can develop more fish by fish hatcheries to increase the population of fish and release large number of fish into the ocean.
We should give the awareness to the general public related to decrease the recreational fishing impact.
Commercial fishing must be ban until we reaches the sustainable level of fish.
There must be place international limits to every country related to limited number of fish they can take.
The asthenosphere and outer core would solidify.
