拓扑学是对图形在任何变形下保持不变的性质的研究。
儿童开始对自己实践那些他人曾经对他实践过的相同行为形式。
The best stories are those that leave something to the imagination.
Among thousands of people, you meet those you've met. Through thousands of years, across the boundless wilderness of time, you happen to meet them, neither earlier nor a bit too late. There is nothing to be said except to ask lightly, "Oh, you're here too?"