Why it is advise to clean the ends of connecting wires before connecting them?

Which force is most responsible for binding together an atom's protons and neutrons? electrostatic gravitational nuclear magnetic

30 points - when can a theory be modified if a new type of technology allows for new observations that raise new questions? a. immediately, while the questions about the theory are being asked b. after new hypotheses related to the theory are tested in experiments c. only after the new observations disprove all parts of the theory d. while scientists begin to think about how the theory could improve

Energy flows from the producer level to the level. is called