Each state of the United States selects two senators to represent their states in the United States Senate. In 1913, the 17th Amendment[?] to the United States Constitution provided for the direct popular election of senators; prior to this, senators were selected by state legislatures.
... O2 and H+. The electrons transfer from the primary acceptor to plastoquinone, then to plastocyanin, producing proton-motive force as with cyclic electron flow and driving ...