Describe how the growth of cities is similar or different from each other.

Essentially, some cities can grow in a "spreading out manner," until they eventually hit their respective municipal borders. However, once a city cannot grow laterally anymore, they grow upwards, this is expressed as the buildings we see in urbanized areas throughout the world.  

where is the picture? ?

question

which are human systems?

the amazon rain forest

the appalachian trail

the george washington bridge

the himalayas

the hoover dam

the north american free trade agreement