What happens to the resistance of a wire as it gets wet

Automobile fuel efficiency is often measured in miles that the car can be driven per gallon of fuel (mpg). heavier cars tend to have lower fuel efficiencies (lower mpg ratings). which variable (weight or fuel efficiency) is most naturally considered the explanatory (predictor) variable in this context?

For which pair of objects would adding the same a

Matter is needed to transfer thermal energy bya. conductionb. convectionc. radiation d. both a & b.