of their own free will

• adj. 出于自愿

of their own free will的用法和样例：

例句

用作形容词 (adj.)

1. She gave up taking drugs all of her own accord.
   她完全是出于自愿而停止吸毒的。
2. Brindley had begun on his own account, out of interest, to survey the waterways that he travelled as he went about his engineering projects for mills and mines.
   布林德雷在为他的磨坊和矿井建筑工程到处奔走的时候，出于自愿和兴趣，对沿途经过的河道进行了勘察。