1.If decent lodging is not built fast enough, slums may spring up instead.
假如合适的寓所建的不够快的话,相反,贫民窟可能涌现。
2.Few had basic plumbing, and soon even the wealthier hutongs had deteriorated into slums.
由于没有基本的排水管道,很快就连较富裕的胡同也彻彻底底地变成了的贫民窟。
4.A billion people are living in slums, not the same billion people, but there is some overlap.
有十亿人生活在贫民窟,虽然与上面提到的十亿人不相同,但他们之间有重叠部分。