I need some help with my science hw about energy, work, and power. It would be greatly appreciated:)

In positive numbers less than 1, the zeros between the decimal point and non zero are significant

In a system, when potential energy decreases, then entropy also decreases. true false

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?