以下是一些樂觀的英文佳句：
1. "Keep your face always towards the sunshine, and you will find happiness everywhere." - Ralph Waldo Emerson
2. "Optimism is the faith that leads to achievement." - Ralph Waldo Emerson
3. "Success is not final, failure is not fatal: It is the courage to continue that counts." - Winston Churchill
4. "Believe in yourself and everything will be possible." - Unknown
5. "Life is like a box of chocolates, you never know what you're gonna get." - Forrest Gump
6. "When you're down, up. When you're in despair, hope." - Unknown
7. "Happiness is not something ready made. It comes from your own actions." - Dalai Lama
8. "Nothing in life is impossible. The word itself says 'try'." - Dr. Thomas Alva Edison
希望這些句子能夠幫助你保持樂觀的心態！