Within the central business district (CBD), tall buildings dominate the scene. Elsewhere in the urban area, and even in transition areas, the most conspicuous visual element consists of _____, generally rising above low-level residential and commercial rooftops. Their visual dominance is interrupted for special-use areas, such as airports or planned industrial districts, but in general, their pervasiveness can be seen in cities throughout North America. Group of answer choices water towers communication lines power lines trees communication towers