What natural disasters possibly caused the collapse of the harappan civilization?

the rebels’ chances of victory at lexington & concord were fairly slim, given the fact that most of them very untrained and they were up against the world's greatest military force.  

swahili is an extremely rich and complex civilization, a set of ethnic groups articulated by a language and a series of cultural elements that fuse the african traditions, islam and indian culture. this growth was largely a result of the indian ocean trading network that brought in not just man-made riches, but also religious ideas, specifically islam, which had a significant impact on the local culture. furthermore, the development of the swahili language gave a common cultural unity to the people.