fron
tier
复数形式
frontiers
1
边疆, 边界
the outer edge of occupied or developed land, beyond which lies unsettled territory
- Pioneers migrated westward, steadily pushing the frontier of settlement into new territories.
先驱者们向西迁移，不断将定居的边界推向新的领土。
- During the 19th century, settlers pushed west across the Great Plains, gradually expanding the frontier of the young American nation.
在19世纪，定居者向西推进穿过大平原，逐渐扩大了年轻的美国国家的边疆。
- Speculators and prospectors often ventured ahead of the settled frontier in search of fertile lands and mineral wealth.
投机者和勘探者经常冒险越过已定居的边界，寻找肥沃的土地和矿产资源。
2
前沿, 新领域
an undeveloped field of study; a topic inviting research and development
3
边界, 边疆
an area located at a border, where two countries or regions meet
- The town lies right on the frontier, making it a strategic location for trade.
该镇位于边境上，使其成为贸易的战略要地。
- Customs officers work diligently at the frontier to enforce immigration laws.
海关官员在边境辛勤工作，以执行移民法。
- The conflict at the frontier escalated tensions between the neighboring nations.
边境的冲突加剧了邻国之间的紧张关系。
- The explorers set up camp at the frontier to begin their journey into uncharted territories.
探险者在边境扎营，开始他们进入未知领域的旅程。
- The soldiers were stationed at the frontier to monitor any movement between the two countries.
士兵们驻扎在边境，监视两国之间的任何动向。