请教曹老师：

She entered the station twenty minutes before the train was due, since her parents had impressed upon her that it would be unforgivable to miss it and cause the friends with whom she was going to stay to make two journeys to meet her. She gave her luggage to a porter and showed him her ticket. To her horror he said that she was two hours too soon. She felt inhere handbag for the piece of paper on which her father had written down al the details of the journey and gave it to the porter. He agreed that a train did come into the station at the time on the paper and that it did stop, but only to take on mail, not passengers. The girl asked to see a timetable, feeling sure that her father could not have made such a mistake. The porter went to fetch one and arrive back with the station master, who produced it with a flourish and pointed out a microscopic 'o' beside the time of the arrival of the train at his station; this little 'o' indicated that the train only stopped for mail. Just as that moment the train came into the station. The girl, tears streaming down her face, begged to be allowed to slip into the guard's van. But the station master was adamant: rules could not be broken and she had to watch that train disappear towards her destination while she was left behind.

1）这一句 The porter went to fetch one and arrive back with the station master, who produced it with a flourish: one 和 it 同一个吗？The porter 拿了，然后给了the station master？另外，produced it with a flourish 很难理解：挥舞着掏（produced it）出来？

2）书上，参考书等怎么都是Just as that moment，而不是Just at that moment ？是不是错了，应该是at, 而不是as ？tears streaming down her face - 可否理解成定语修饰the girl ？

3） while she was left behind - while 究竟是“当...时候”，还是“对比两件事物：然而” ，这个while究竟应该怎么正确理解用法含义？

以上3个问题，麻烦老师分析指正，谢谢。