What happened in the 1920's

The great depression and the roaring 20s. The roaring 20s were a fun time that nobody cared how much money they spent and that created the great depression.

answer; /// i believe that the correct answer is (d)the huang he river valley;

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.