Free points for anyone

Which of the following is not am example of a polymer? protein nylon kevlar concreta

In a voltaic cell, electrons flow from the (positive/negative) to the (positive/negative) terminal.

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