Did I rewrite this sentence correctly?

[vkhu]

I was told to rewrite the sentence using the word passed

They didn't reply to my letter for two months
->Two months passed by before they replied to my letter

Did I got it right? It was taken from the book Use of English by Mark Harrison but my key page got ripped out. Some one check it for me.

 

[Tdol]

It's OK.

 

[bhaisahab]

Did I get it right? It was taken from the book Use of English by Mark Harrison but my key page got ripped out. Some one check it for me.

Bhai.