Hello!
1.New York is more crowded than Bucharest.
Bucharest isn't as crowder as New York.
2.Bucharest is more interesting than New York.
New York isn't as interesting as Bucharest.
3.Bucharest is more older than New York.
New York is not as old as Bucharest.
4.New York is more expensive than Bucharest.
Bucharest isn't as expensive as New York.
5.Bucharest is more warmer than New York.
New York isn't as warm was Bucharest.
6.New York is more busy than Bucharest.
Bucharest isn't as busy as New York.
Good luck with your homework!