Which of the following distinguishes a secondary source from a primary source? a secondary source is much more difficult to find. a secondary source has the benefit of hindsight. a secondary source is not as reliable as a primary source. a secondary source is always preferable to a primary source.

What two different approaches did the knights of labor and the american federation of labor take in building a union organization? a) the knights of labor accepted only unskilled workers; the american federation of labor accepted only skilled workers. b) the knights of labor accepted skilled and unskilled workers; the american federation of labor accepted only skilled workers.c) the knights of labor refused to accept african american or chinese workers; the american federation of labor accepted all workers.d) the knights of labor accepted workers from a single industry; the american federation of labor accepted workers from several industries.