Respuesta :

The missing word is 'efficiency'

Answer:

Efficiency

Explanation:

Efficiency refers to the percentage of energy that is used to perform any work. The higher the efficiency of a fuel, the higher is percentage of energy used to do work. In other words, the efficiency of a fuel can be increased by increasing the amount of energy involved in any function. This would reduce the loss of energy and heat leading to more efficient fuels.

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