Why did the Qin Dynasty collapsed

Qin Shi Huang's son was killed, and the dynasty collapsed entirely.

Explanation:Upon the First Emperor's death, China plunged into civil war, exacerbated by floods and droughts. In 207 BCE, Qin Shi Huang's son was killed, and the dynasty collapsed entirely. Chaos reigned until 202 BCE, when Gaozu, a petty official, became a general and reunited China under the Han Dynasty.

xinhai revolution

Explanation:

because of xinhai revolution  (1911 revolution)

alliances in ww1 were different from ww2 because the entente in ww1 made up of serbia,russia,france,britan,japan and italy later america  and all allied in a sort of balance of power and too keep germany,austria-hungary,and the ottomans down. russia allied the serbians in order to exert its influence in the balkans while france allied the russians because france was still in dismay and insulted after the defeat to the germans during the unification of germany and britian allied the belgians after the germans invasion of belgium.in ww2 the alliances were in a preemptive attempt to deter any further wars into happening while germany and italy allied since they were insulted and humiliated after the previous war while also sharing a similar ideology of facsim along with japan which all 3 had a want for world domination and agreed to assist one another in the endevours 

explanation: