duration of existence的用法和樣例：
例句
- During its brief existence, the pion carries momentum from one nucleon to the other.
在它短暫的存在期間內，它將動量從一個核子帶到另一個核子。 - On the other hand, if you mean duration of existence as an earth feature, then the Appalachians certainly are among the timeless landscapes of the world.
另一方面，如果你把存在期間看作是地球的特點，那麼，阿帕拉契山無疑是在這地球上永恆的自然景觀的其中之一。
