The United States has the most reserves of which fossil fuel?

coal

natural gas

petroleum

wind

Which one of the following research methods can show cause and effect

Apatient has a history of poor nutrition. he has skin rashes, bleeding gums, and a cut that hasn’t healed in a long time. what vitamin deficiency most likely caused this symptom?

Large electric fields in cell membranes cause ions to move through the cell wall. the field strength in a typical membrane is 1.0 x 10 7 n/c. what is the magnitude of the force on a calcium ion with charge +e? what is its acceleration? is it possible for a particle with the same charge as as calcium to have a different acceleration if placed at this location? what would change the acceleration: mass of the particle? diameter of the particle?