What event triggered the start of world war i?

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.

Which three of these issues did europe face after the war? *all that apply* a. a worldwide pandemic b. monarchy in britain c. communism in russia d. a worldwide cancellation of debts e. dislocated refugees

What significance does alfred t. mahan have on expansion and imperial policies of the late 1800s?