By the end of april 1975, which city fell to the north vietnamese army, leading to the unification of vietnam?

According to documents in wiesner et al., why has access to water been such an important factor in the rise of complex societies? how did ancient societies address the problems associated with harnessing these powerful resources? how have historians assessed and addressed this issue? cite the appropriate documents relevant to the response.

During the era of european expansion, what was the biggest reason for spain’s push for exploration?

How did the treaty of versailles cripple germany after world war one ?