天险不可升也，地险山川丘陵也。王公设险以守其国，险之时用大矣哉。
释义：天之险在于高不可升，地之险在于山川丘陵。王公设险以保卫国家，险的功用非常大。
Core technologies cannot be bought; they must be developed independently.
每一本书都是一次旅程，每一页都是踏入未知的一步。
The transition to cleaner energy must be inclusive, ensuring no communities are left behind.
变革在开始时最艰难，在中期最混乱，在结束时最美好。
"Every saint has a past, and every sinner has a future."