11.   Her letters were the only thing that kept me going while I was in prison.

12.   Her letters were the only things that kept me going while I was a prisoner.

13.   I expected to be disappointed, though the letter was now my only hope.

14.   In fact, the letter is almost obsequious.

15.   Knowing that the letter might have been one of them continues to give me great satisfaction.

16.   Letters of Request are to be executed expeditiously.

17.   My letter was not the sort of letter you spent months writing and rewriting.

18.   Nobody took any notice, but official letters were always polite.