The heart gives direct functional properties to what organ of the body

The frequency in wich you perform certain exercise depends on the blank of the exercise

Select all of the possible methods of aids transmission.

The famous scientist galileo galilei did several experiments with sloping planes, which he rolled metal balls down so that he could study motion. by changing the slope, he could study how the speed at which the ball rolled was affected. what was the dependent variable in galileo's experiment?