例句：Spencer was taken on for a three-month trial period before being accepted as apermanent member of staff.
在斯宾塞被接受为固定雇员之前经过了三个月的试用期。
perpetual adj. 永久的
例句：They hoped to live ill perpetual happiness.
他们希望生活在永久幸福之中。
everlasting adj. 永恒的，持久的，无止境的，耐用的
例句：The conflicting interests of producers and consumers will be everlasting.
生产者与消费者之间的利益冲突将永远存在。
eternal adj. 永恒的，永远的，不灭的，没完没了的
例句：Cherry felt eternal gratitude to him for saving her life.
切莉终生感激他的救命之恩。
lifetime n. 一生，终生，寿命
例句：Tony is a legend in his lifetime for his scientific discoveries.
托尼的科学发现使他成为传奇人物。
invariably adv. 不变地，总是 n. 总量
例句：It invariably rains when l go on vacation.
我去度假时老是下雨。
transient adj. 短暂的，瞬时的 n. 瞬时现象
例句：Angela's feeling of depression was transient.
安吉拉那抑郁的心情一会儿就过去了。
instantaneous adj. 瞬间的，即刻的，即时的
例句：Her mother accidentally swallowed the poison and death was instantaneous.
她妈妈无意中吞下毒药，即刻死去。
