Final answer:
To join the sentences "I should have cleaned my room" and "I played a game," use the conjunction "Instead" at the beginning of the second sentence, forming "I should have cleaned my room; instead, I played a game." Additionally, when correcting sentences for proper punctuation, ensure clarity in structure and meaning.
Step-by-step explanation:
When asked to rewrite the sentences "I should have cleaned my room" and "I played a game" with a joining word at the beginning of the second sentence, an appropriate conjunction is "Instead". This is because the second action happened as an alternative to the first. Therefore, you could join these two sentences to say: "I should have cleaned my room; instead, I played a game." This clearly connects the two activities, implying a choice was made to prioritize gaming over cleaning.
As for the exercises provided, each requires the identification and correction of punctuation, particularly with commas. With the right punctuation, clarity and meaning can be enhanced in the sentences. For example, in mixed sentence 1, the corrected version might read: "Learning to ballroom dance has shown increased agility, and you live longer," eliminating the unnecessary "it."