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。
Dear Seth,
You are only three years old, and at this point in your life you are not able to understand this letter. But some day when you 1 , I hope you will find something 2 in what I am going to share with you.
Life can be 3.There will be people in your life who won't be very nice. They'll 4 you because you are different, 5 for no good reason. You will also face heartbreak and might be 6 by those you love. I hope you don't have to face these too much. But such things 7 .
Be open to life anyway. You'll find cruelty(残忍) and 8 in your journey through life, but don't let that 9 you from finding new things. Don't retreat(退却) from life, and don't 10 or wall yourself off. Be open to new things, new experiences and new people. You will 11 many times, but if you allow that to stop you from trying, you will 12 many chances. Do remember failure is a stepping stone to 13.
You will meet many people who will try to do 14 than you, in school, in college, and at work. They'll try to have nicer cars, bigger houses, nicer clothes, and so on… To 15, life is a competition. However, I believe life is a 16. If you always try your best to17 others, you are wasting your life. Learn to enjoy your life 18 and you will make it a journey of 19 of learning and of love.
Finally, know that I love you and always will. You are 20 a really wonderful journey, and I will always be there for you.
Love,
Dad
