名词

1. The frontiers of medical knowledge are being pushed farther outwards as time goes on.
医学知识的新领域正随着时间向前推进。

2. Everything is quiet on the frontier.
边境上一切安静。

3. Professor Field is devoted to the exploration of the frontiers of medicine.
菲尔德教授致力于探索医学研究的新领域。

1. 边界;边境
A frontier is a border between two countries.

e.g. It wasn't difficult then to cross the frontier.
那时穿越边境并不困难。

noun

1. an undeveloped field of study
a topic inviting research and development

e.g. he worked at the frontier of brain science

2. an international boundary or the area (often fortified) immediately inside the boundary

3. a wilderness at the edge of a settled area of a country

e.g. the individualism of the frontier in Andrew Jackson's day