Student or Learner
'Urban sprawl increases the amount of concrete and asphalt, thus holding in the heat and making it even warmer than it would have been had sprawl not occurred." In this sentence,
1,what does it mean for 'holding in the heat'?
2,what is the subject of 'making it even warmer than..
3,than it ,what does it stand for 'it'?
4,"than it woud have been had sprawl not occurred" what the grammatical structure?
Thanks in advance