曾经有一次的英文

once upon a time

one day

One day 或Some day有一天Once a time有一次相信我，我是专业英语的！

one day, some day 有一天，某日once, this one time, 有一次

Once I was late for English class,The teacher ask me what happen,I didn't understand his word,so i didn't say anything,However,then i was drived out by the teacher.