to push (back) the frontiers
01
to expand the boundaries or limits of knowledge, discovery, or understanding, typically in science, technology, or exploration
例子
Explorers have always sought to push the frontiers of human knowledge by reaching uncharted territories.
02
to extend the boundaries of a region or country, often through exploration, colonization, or territorial conquest
Collocation例子
The westward expansion of the United States in the 19th century pushed the frontiers of the nation.
