76. We, according to the passage, tend to observe cities ____.

1. chronologically
2. longitudinally
3. sporadically
4. horizontally

77. We think about a city as ____.

1. a spatial event
2. a symbolical world
3. a social environment
4. an interrelated system

78. Cross-sectional studies show that cities ____.

1. are structured in three dimensions
2. are transformed rapidly in any aspect
3. are resilient and long lasting through time
4. change slowly in spatial and social structures

79. The author is drawing our attention to ____.

1. the equilibrium of urban spatial structures
2. the intrinsic dynamics of urban change
3. the fixed spatial infrastructure
4. all of the above

80. The conventional notion, the author contends, ____.

1. presents the inherent nature of a city
2. underlies the fixed spatial infrastructures
3. places an emphasis on lesser cycles of time
4. hinders the physical change of urban structure

(Reference keys.)