Salt deposits and moisture threaten to destroy the Mohenjo-Daro excavation in Pakistan, the site of an ancient civilization that was destroyed multiple times by flooding of Indus river…
Now in this sentence, “that” can be omitted (obviously along with “was”)
Question: Here the site cannot do the action of destroying and hence it is clear that destroyed is a verb-ed modifier.
But consider another version of this sentence:
"Salt deposits and moisture threaten to destroy the Mohenjo-Daro excavation in Pakistan, the site of an ancient civilization that flourished at the same time as the civilizations …"
The answer = “that” is required because if you omit it, the sentence will be a run-on sentence.
Question:Here the site cannot do the action of flourishing , and also the civilization cannot do the action of flourishing?? so here also "that" is not required. The flourished can do the action of verb-ed modifier and modify the noun(civilization)..................Is this logic correct??