拓扑学是对图形在任何变形下保持不变的性质的研究。
Topology is the study of the properties of a figure that are unchanged by any deformation.
Freedom is not merely the opportunity to do as one pleases; neither is it merely the opportunity to choose between set alternatives. Freedom is, first of all, the chance to formulate the available choices, to argue over them - and then, the opportunity to choose.
跨国合作是拯救海洋的关键。
我想像鸟儿歌唱一样作画。
时间是一个小偷，偷走瞬间，只留下阴影。