involuntarily
adv. 无心地；不自觉地；偶然地
例句
His left eyelid twitched involuntarily.
他的左眼皮不由自主地跳着。
《柯林斯英汉双解大词典》
He cried involuntarily, as he looked at East Gate, which, in those days, was at the end of East Street.
他望着东门不由自主地叫了起来，那时候东门就在东街的尽头。
His thoughts were so elastic, his heart so tender; and involuntarily he picked one of the nearest flowers.
他的思维真跳跃，他的心真温柔；他不由自主地摘了一朵最近的花。
