法律义务不仅仅是道德义务加上制裁。
Legal obligations are not merely moral obligations backed by sanctions.
你必须愿意失败才能成功。
不为苏联解体而惋惜的人没有良心，想恢复苏联的人没有头脑。
The beauty of mathematics is that it is eternal, it doesn't change.
Sustainability isn't an option anymore—it's a necessity for survival.