I think it's important to be able to laugh at yourself.

任何有价值的人生都是一个持续的寓言。

The future of liberal democracy depends on its ability to adapt to new challenges and to maintain the support of its citizens.

Safety isn't just a policy, it's a culture that must be lived every day in our mines.

The best stories are those that can be read again and again with ever-increasing pleasure.

随着劳动分工和机械应用的扩大，工人之间的竞争加剧，他们的工资也越来越低。

这类波可以像光波一样被反射、折射和偏振。