(Science)How does the heart keep the blood flowing throughout the body? It contracts and relaxes
It inflates and deflates
It inhales and exhales
It opens and closes

How can you use chemical equations to predict the products of the reaction you can carry out?

If an area has high air pressure and low humidity, what type of weather will it most likely have? plz !

The twister and runaway train are two coasters at the same amusement park. both coasters start at the same height. the coaster for the twister is twice the mass of the coaster for the runaway train. which roller coaster has greater gravitational potential energy at the start of the ride?