Answer: Rare Fortune
Explanation:
Context clue is the additional information provided by an author that can help a reader understand a word more clearly. It can be in the form of an explanation, an example, synonym, antonym, word-structure, etc.
In the given expression, elated means that Ah Fo felt very happy and excited at his prospect probably because it had never happened to him before.
Rare fortune means an event that is incomparably good. It could work as an adjective to describe an event which hardly occurs. It provides an explanation as to why Ah Fo was excited. Something very good had happened to him.
