A is the answer to the question you asked
Active voice is when the subject performs the verb. The answer is 'Our puppies played at the cool new dog park' because the puppies are playing, while the rest of the verbs in the other choices are not being acted at by the subject.
Yes, me is the correct pronoun to use in the sentence <em>Mark studied all afternoon with Marcus and ______.
</em>No other pronoun can be used in this example, because you need an object pronoun, and other options are subject.<em>
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