frontier

复数：frontiers

1. [C]边界,边境 the edge of the land of one country
2. [S]开发地区的边缘,边远地区 the border between settled and wild country
3. [P]尚待开发的领域 a border between what is known and what is unknown

• close a frontier关闭边境

• the frontier between在…之间的界线
• have frontiers with与…接壤

new frontier新边疆；新境界

frontier trade边境贸易

efficient frontier有效边界；效率前缘

frontier orbital前沿轨道

1. We were turned back at the frontier.
   我们在边界那儿被赶了回来。
2. The frontier ranges from the northern hills to the southern coast.
   边界从北部山地一直延伸到南部海岸。
3. Everything is quiet on the frontier.
   边境上一切安静。
4. This new frontier incident probably means war.
   这个新的边境事件可能导致战争。
5. The minority of us are confronted with difficulty in the frontier of the major.
   我们少数人在该专业尖端领域面临困难。
6. The frontiers of medical knowledge are being pushed forwards as time goes on.
   医学知识的新领域正随着时间向前推进。
7. He came from the remote frontier.
   他来自遥远的边疆。