该条约的签署标志着通往欧洲联盟道路上的一个重大里程碑。

The signing of the treaty ___marked a major milestone on the road to European union.

这些书大多具有很高的科学性，标志着一个启蒙与技术新时代的开端。

These books, most of which are very scientific, ___marked the beginning of a new era of enlightenment and technology.

这位艺术家的最终展览标志着这座城市文化景观的一次深刻转变。

The artist's final exhibition ___marked a profound shift in the cultural landscape of the city.