Glenn would like to provide a more detailed thesis statement for his paper which of the following could replace sentence 6

i think sylvia like her but she not trying to show it and i think rainbow will forgive her.

explanation:

"urban sprawl, the spreading of large developments of housing and shopping areas around a city’s center, has many negative cultural and environmental effects. " (from your link)

so, your answer is: it has a negative effect on the environment, otherwise known as c~hope this mate. 

if flooding were to go unchecked, steel support beams in buildings would rust.