Why is alternating current more effective at long–distance travel than direct current?
the power lines are made out of conductors.
transformers increase or decrease voltage as needed.
the ac generator is more efficient.
ac has lower voltage than dc.

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 is not true about oxygen-17 and oxygen-18?

Organelles are 1. responsible for producing power for the cell 2. tiny structures in the cell that carry out the cell's activities 3. responsible for digestion in the cell 4. found outside of the membrane