What is corona virus? can you please help me with this.

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?

About how many individuals in the us go bankrupt each year due to medical bills?

Why do you need two different circuits of blood vessels in your body?