Though Gary was initially ___ and unsure about buying a house near the River, Penny spoke about the home with great certainty and and eventually persuaded him to make the purchase.

Though Gary was initially scared and unsure about buying a house near the river, Penny spoke about the home with great certainty and positivity and eventually persuaded him to make the purchase.

Explanation:

The blanks were filled based on the context clues that the sentence presents. In this case, words were chosen which, when added to the sentence, kept the message coherent and cohesive in the text.

Context clues occur when the message and the context with which the sentence was written, allow the reader to recognize some words, their meanings and reasons for having added the sentence.