1. The perpetual argument is that funds are tight, that we have more pressing problems here on Earth. 永恒的争论是资金紧张，我们在地球上有更紧迫的问题。
2. The advantage of biological control in contrast to other methods is that it provides a relatively low-cost, perpetual control system with a minimum of detrimental side-effects. 与其他方法相比，生物防治的优点是它提供了一种成本相对较低、有害副作用最小的永久性防治系统。
3. She's a perpetual student. 她是个终身学习者。
4. He was elected perpetual president. 他被选为终身会长。
5. We lived for years in a perpetual state of fear. 多年来我们一直生活在恐惧中。
