The best time to plant a tree was 20 years ago. The second best time is now.
种树的最佳时间是20年前,第二好的时间是现在。
我们说的每一个词都承载着我们的历史和未来的希望。
Mathematics advances not by the efforts of individuals alone but through the collective work of generations.
成功是唯一的选择,失败不是。