【问】 (1) I recognized him at the first moment I saw him.

(2) We liked each other from the first instant we met.

(3)It was full dawn by the time he reached the road.

斜体部分与前面的名词是什么关系?如果是定语从句，那么其间省略了什么词语?

【答】 可以认为在名词中心词与定语从句之间省略了关系副词that或when。实际上，也可以不省略这个that或when：

1. At the first time that I saw him，I recognized him. (CGEL)

第一次看到他，我就认出了他。

2. I sent you the news from the first instant that I heard it.

我一听到这个消息，就寄给了你。

3. At the first moment that he had said it he knew what mistake he had made.

他刚一说出了这件事，就知道他犯了一个什么样的错误。

4. There have been moments in history when remarkable progress was made in relativelyshort periods of time. (TOEFL，84.5)

历史上有过这样的时候：在相当短的时期内取得了惊人的进步。