Afixed asset's estimated value at the time it is to be retired from service is called a. residual value b. book value c. carrying value d. market value

a.residual value 

Explanation:

Book value or carrying value is the value of the asset on the balance sheet. It is equal to cost of the asset less accumulated deprecation.

Market value is the value of an asset in the market.

I hope my answer helps you

metallurgy is your answer

the "study of metals and the process of refining ("

note that it says metal. metallurgy has the word "metal" in it, and so is most likely your answer (and is your answer).

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ans.

heterothermic organisms include those organisms that can switch between homeothermic (having body temperature higher than environment) and poikilothermic (having variation in internal body temperature) strategies.

some migratory birds show heterothermy as they decrease their metabolic rate during cold nights to keep their body temperature low. drop in metabolic rate allows increase in production efficiency of birds that reduces the internal body temperature to make it equal to external cold temperature during cold nights.

thus, the correct answer is 'birds allow their temperature drop in order to increase their production efficiency.'