During resistance exercise, muscles are
a. working against a force
b. repeatedly contracted
c. concerted in movement
d. all of the above

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.

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

What is a good example of instantaneous speed