Sentence Correction (SC) | Re: In the mid-1970s, since birds were overcome by pollution,

In the mid-1970’s,since birds were overcome by pollution, and routinely falling from the sky above Los Angeles freeways, this prompted officials in California to devise a plan that reduced automobile emissions.

A. since birds were overcome by pollution, and routinely falling from the sky above Los Angeles freeways,this prompted officials in California to devise aplan that reduced


this is incorrect. This should be used as a possessive adjective only and not as a pronoun replacing a noun. Also, it is trying to replace a verb (falling).
Also, plan to is the correct idiom in this case (should avoid plan to only if the sentence was like 'to plan to something').
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