Student or Learner
I came across this problem on the internet:
For 28 years, the stark cement blocks of the notorious Berlin Wall reminded Germans and travelers to Germany that they were on the front lines of the Cold War. As the western city rebuilt (fill in the blank) its cement cage, a traumatized population began to express their anger in paint.
The answer is "rebuilt into". However, I do not understand the phrase "rebuilt into its cement cage".
Could you enlighten me please?