• 2022-06-05
    backbone (
    )
    A: to move back and
    forth or up and down with quick motions.
    B: the amount of a
    substance that is contained in something else.
    C: a daughter of
    one's brother or sister; a daughter of one's brother-in-law or
    sister-in-law.
    D: the row of bones
    that runs along the center of the back; spine.