Learn from yesterday, live for today, and hope for tomorrow.
借鉴昨天，活着当下，憧憬未来。
Yesterday is the past, we can learn something from it, such as why we succeeded, why we failed, what we can do to improve ourselves. Bear in your mind that it is no use to crying over yesterday's faults or failures.
Today is the most important, live today meaningfully and we can avoid the future failure.
Tomorrow means hope, and hope is one of the best things we can have.
Friendship could cross over space and time.
友谊可以穿越时空。
Frequent communications can make the friendship more solidate.
And warm smile on your face can make you much more attrative.
Today, I have encountered a problem in my program.
Unfortunately, I can't find out where the problem lies in, maybe the keyboard drivers, or the x-window system, or the qt library, or the program itself.
I often feel tiresome, for no reason, or for such trival problems.
It makes me feel that no matter what I have done, the result may be the same.