What made Athens difficult to attack directly? Athens was located far away from other city-states.
The harbor of Athens was protected by tall mountains.
Athens was secured by walls and the city center was on top of a hill.
Athens was on an island and was protected by water on all sides.

Which statements are there

The us is first  the  u.s. economy  remains the  largest in the world  in terms of nominal  gdp. however, the  u.s. economy  loses its spot as the number one  economy  to china when  measured  in terms of  gdp  based on ppp. in these terms, china's  gdp  is $23.19 trillion exceeds the  u.s. gdp  of $19.42 trillion