既然定语从句中关系副词在正式文体中不可省略，为什么下面这句话中“she was traveling”前省略了when？

Question

Such an experience befell a certain young girl the first time she was traveling alone.（一个小姑娘第一次单独出门就碰到了这种情况。）——《新概念英语》
这里的“she was traveling”是修饰状语“the first time”吗？

Answer 1

the first time本身就可以作连接词词组引导状语从句。
用作关联词的关系副词有when，where，why等。when在从句中用作时间状语，其先行词须是表时间的名词。如：
(51)We will put off the picnic until next week, when the weather may be better. 我们打算把野餐推迟到下周，那时天气可能转好。(关系副词when的先行词是next week)
(52)He came last night when I was out. 他昨晚来时我出去了。(关系副词when的先行词是last night)
since，before，after亦可用作表时间的关系副词。如：
(53)Every hour since I came has been most enjoyable. 我来之后的每一个小时都是非常好玩的。(since用作关系副词)
(54)On the day before we left home there came a snowstorm. 在我们离家的前一天，下了一场暴风雪。(before用作关系副词)
(55)The year after she had finished college she spent abroad. 她大学毕业后的一年是在国外度过的。(after用作关系副词)
that有时亦可用作表时间的关系副词。如：
(56)It happened on the day that I was born. 那件事是在我出生的那一天发生的。(that=when)
where在从句中用作地点状语，其先行词须是表地点的名词。如：
(57)They went to the Royal Theatre, where they saw Ibsen’s “The Doll’s house”. 他们去皇家剧院看了易卜生的《傀儡家庭》
(58)The place where Macbeth met the witches was a desolate heath. 麦克白遇见女巫的地方是一片荒原。
where的先行词亦可是有地点含义的抽象名词。如：
(59)He has reached the point where a change is needed. 他已到了需要改弦易辙的地步。(where的先行词point是抽象名词)
why在从句中用作原因状语，其先行词只有reason。如：
(60)That is no reason why you should leave. 那不是你必须离开的原因。(why先行词是reason)
(61)He refused to disclose the reason why he did it. 他拒绝透露他做那件事的原因。(why先行词是reason)
有时why可以省去。如：
(62)That’s one of the reasons I asked you to come. 那是我要你来的原因之一。(reasons后省去why)
有时why可用that代替。如：
(63)The reason that he died was lack of medical care. 他死于缺乏医疗。(why由that代替)
希望我能帮助你解疑释惑。

Answer 2

是的，这是个后置补语，用来作the first
time 的状语补足语，表示进一步说明情况。明白了吗追问

您好，不是的，the first time本身就可以做连词引导状语从句，类似的还有any time, each time, every time等短语，都可以引导状语从句。

追答

你好，您的解释是错误的

追问

您好，以下内容摘自“时间状语从句”的百度百科：
as soon as, the moment, every time, each time, the minute, the instant, the day, the week, the year, the first time,next time, any time, the last time, all the time, from the time, by the time, immediately, instantly, directly等表示时间的词语，后面也可以接时间状语从句，表示“一……就……”