Vì sao con người phải tạo ra các giống câu trồng hoặc vật nuôi mới?

Improving livestock breeds to allow greater feed efficiency and other desirable traits. food production, restoration of threatened and endangered species populations, wild stock population enhancement, the building of aquariums, and fish cultures and habitat restoration.

Explanation: hope this helps

the truman doctrine was an american foreign policy whose stated purpose was to counter soviet geopolitical expansion during the cold war. it was announced to congress by president harry s. truman on march 12, 1947, and further developed on july 12, 1948, when he pledged to contain threats to greece and turkey.

the answer that best describes the relative refractory period in the neuron is the resting membrane potential is restored, but concentrations of sodium and potassium are not restored to their original state.

the refractory period is the time during which another stimulus given to the neuron will not lead to a second potential. thus, because na+ channels are inactivated during this time, additional depolarizing stimuli do not lead to new action potentials.  

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