once upon a time很久很久以前改成once a time不行吗?upon在这里起什么作用啊?

once upon a time很久很久以前改成once a time不行吗?upon在这里起什么作用啊? Once upon a time once upon a time once upon a time once upon a time中文 .英译中..once upon a time..) 英语翻译用once upon a time once upon a time 课文翻译 京城往事 ONCE UPON A TIME怎么样 once upon a time的意思 Once upon a time怎么读 You are my once upon a time . Once upon a time,there was a pretty ,fresh Once upon a time there was a poor old fisherman.ONCE UPON A TIME 做什么成分? once upon a time 谁能帮我翻译下~ 翻译Once upon a time,there lived an olive tree. 完形填空 Once upon a time,there were. Once upon a time,there was an emperor...