Answer:B,C,D
Explanation:
Thermodynamic efficiency is given by

efficiency can be increased by Keeping
constant and increasing 
Keeping
constant and decreasing
by increasing 
by decreasing
ratio
Answer:
i think it would be B, a large factory
Explanation:
How can one explain<span> and predict the </span>interactions between objects<span> and within a system of </span>objects<span>? ... through </span>electric or magnetic fields to illustrate the forces between objects and the changes in energy of the objects due to the interaction<span>. ... </span>Forces<span> at a distance are </span>explained<span> by fields (gravitational, </span>electric<span>, and magnetic) ...</span>