Answer:
Most reasons are self-explanatory. Clearly, you'll need access to water for drinking. Location near to a large body of water is also useful for transportation and trade. Local access to a plethora of natural resources is obviously also highly beneficial, you need this stuff to build cities.
Step-by-step explanation:
Towns began to develop along river valleys, where water was available. There were some important reasons for this. The land along the rivers is fertile. If there is fertile land, then crops can be grown.