What did the etruscians teach the romans?

The Etruscans taught the Romans both engineering and building skills. They also decisively influenced the classical Roman architectural style. They also developed the economy of the city, for instance by draining the marshes adjacent to Rome.

credit to : https://dailyhistory.org/How_did_the_Etruscans_shape_Roman_history_and_society%3F

sumerians were responsible.

the triple alliance. germany and austria-hungary were already allies by 1879 when, worried about a threat from russia, they formed the dual alliance. italy joined the group in 1882. there was a concern about a possible attack from france and the alliance needed powerful friends to defend it.