You'll never achieve anything if you don't study harder.
如果你不更加努力地學習, 你將永遠不會有所成就。
It's the answer that led those who've been told for so long, by so many, to be cynical and fearful and doubtful about what we can achieve, to put their hands on the arc of history and bend it once more toward the hope of a better day.
That's the true genius of America; that America can change. Our Union can be perfected. What we've already achieved gives us hope for what we can and must achieve tomorrow.