The discoveries of the tombs and mummies must have been breathtaking for those lucky few that found them.

"that" or "who"?

What is it that you are supposed to do? I'd ask the question "What must have been breathtaking? answer = the discoveries

Sra

or are you supposed to add either "that" or "who?" Then "for the few who found..."

Sra

The discoveries of the tombs and mummies must have been breathtaking for those lucky few who found them.

In this sentence, "who" is referring to "those lucky few [people]..."

We use "that" to refer to things, "who" to refer to people.

To determine whether to use "that" or "who" in a sentence, you need to consider whether you are referring to a person or a thing. In this case, the sentence is talking about the lucky few who found the tombs and mummies. Since the tombs and mummies were discovered by people, the correct pronoun to use would be "who."