sentence: The skyscraper provides more space for excess population . However , the building will produce more pollution if the skyscrapers are constructed from modern materials , such as steel and concrete .
modified: The skyscraper provides more space for excess population ; however , the building will produces more pollution when the skyscraper constructs by modern materials , such as steel and concrete .
transformation: PUNCT, VERB:FORM, OTHER, NOUN:NUM, OTHER, PREP