1. But the Buffalo nickel, produced from 1913 to 1938, honored a pair of connected tragedies from the settlement of the American frontier — the destruction of the buffalo herds and the American Indians.
    但1913至1938年间发行的野牛硬币，却是为了纪念由美国拓居引起的两起相互关联的悲剧--野牛群的灭绝和美洲印第安人的毁灭。

2. We must show our passports at the frontier.
    在边境我们必须出示护照。

3. In short, the individual in conflict with himself and his frontier environment.
    总之，主人公是一个自相矛盾，又与他的拓荒环境相矛盾的人物。

4. His hero was firmly rooted in both the history and the mythology of the vanished frontier.
    他扮演的角色建立于西部历史和消失了的新垦地的神话之中.

5. And in both the history and the mythology of the vanished frontier.
    也扎根于有关已经消失的拓荒生活的历史和神话之中。

6. You fumble to find your passport when you cross a frontier.
    或者当你出境时，要摸索着寻找护照。