Question

Loosened rocks may tumble down canyons when it is raining heavily.

Answer 1

The correct answer would be  loosened because a participle is used as for an adjective or adverb  for ex.  Billy broke his arm playing ball. the participle is broke.

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Answer 2

Answer:

Loosened.

Explanation:

Participles are words that are formed from a verb, but acting as a noun or adjective in the sentence. They are used in sentences to modify the verbs or nouns, or the noun/verb phrases.

Loosened rocks may tumble down canyons when it is raining heavily

In the above sentence, "loosened" is a verb in itself but when put along with a noun "rocks", it acts as an adjective. So, it becomes the participle in the sentence. It changes the nature of the noun "rocks".