How many objects to newton’s first and second laws deal with

Which sentences describe disadvantages of burning fossil fuels instead of using hydrogen fuel cells? burning fossil fuels contributes to climate change. burning fossil fuels takes place inside expensive fuel cells. fossil fuels aren't widely available, but pure hydrogen is. fossil fuels are nonrenewable.

The passing of heat through a material while the material itself stays in place. a. radiation b. conduction c. convection

What is the force that opposes motion and works against the downward pull? a) friction b) gravity c) weight d) acceleration