PLEASE HELP QUICK!!!

According to the phase diagram for water, how is the state of water determined? proceed up a vertical line at any given temperature read the phase at the intersection of any given temperature and pressure at a given pressure, proceed horizontally to the s-l or l-g line

Which best represents the law of conservation of mass ?

Is there a point between a 10 nc charge and a 20 nc charge at which the electric field is zero?