Why would europeans have to cooperate over use of rivers like the tagus, rhine, elbe, and danube?

what are the choices?

athenian democracy developed around the fifth century bc in the greek city-state (known as a polis) of athens, comprising the city of athens and the surrounding territory of attica, and is often described as the first known democracy in the world. other greek cities set up democracies, most following the athenian model, but none are as well documented as athens'.

it was a political system of direct democracy, in which participating citizens voted directly on legislation and executive bills. participation was not open to all residents: to vote one had to be an adult, male citizen, i.e., not a foreign resident, a submissive or a woman, and the number of these was "probably no more than 30 percent of the total adult population."[1]

the longest-lasting democratic leader was pericles. after his death, athenian democracy was twice briefly interrupted by oligarchic revolutions towards the end of the peloponnesian war. it was modified somewhat after it was restored under eucleides; the most detailed accounts of the system are of this fourth-century modification rather than the periclean system. democracy was suppressed by the macedonians in 322 bc. the athenian institutions were later revived, but how close they were to a real democracy is debatable. solon (594 bc), cleisthenes (508/7 bc), and ephialtes (462 bc) contributed to the development of athenian democracy. cleisthenes broke up the power of the nobility by organizing citizens into ten groups based on where they lived rather than on their wealth.

hope this !