阅读下面短文，从短文后各题所给的四个选项(A、B、C和D中)，选出可以填入空白处的最佳选项。
“How did you do it, Dad? How have you 1 not to take a drink for almost 20 years？” It took me almost 20 years to have the2to even ask my father this very 3question. When Dad first4drinking, the whole family was on pins and needles5 he got into a situation that, in the past, would have started him drinking again. For a few years we were6to bring it up for fear that the drinking would begin again.
“I had this little7 that I would recite to myself8four to five times a day.” was Dad's9to my 18 year old unasked question. “The10 were an instant relief and constant reminder to me that things were never so 11that I could not handle them，” Dad said. And then he 12the poem with me. The poem's simple, yet profound (深奥的) words13became part of my daily routine as well.
About a month after this talk with my father, I14a gift in the mail from a friend of mine. It was a book of affirmations (断言)with one affirmation listed for each15of the year.
I16opened the book to the page of my birthday to see what words of wisdom this book had in store for me.17of disbelief and appreciation rolled down my face. There, on my birthday, was the18poem that had helped my19for all these years! It is called The Serenity Prayer.
God, give me the serenity (平静) to accept the things I cannot change, the courage to20the things I can, and the wisdom to know the difference.