意思:
adv. 一次曾经
conj. 一旦
n. 一次，一回
I've been to that nightclub once.
那家夜店我就去过一次。I met Miquela once， briefly.
我见过蜜凯拉一次，时间很短。
Just for once he arrived on time.
只有这一次他按时到了。
The water is fine once you're in!
你一旦下了水，就会觉得水里挺舒适。
I've only been there once.
我只去过那里一次。
She once ruled over a vast empire.
她曾统治过一个幅员辽阔的帝国。
