Final answer:
The participial phrase that best completes each sentence is 'Already melting under the bright winter sun'. In the second sentence, Julia brushed her teeth after eating.
Step-by-step explanation:
The participial phrase that best completes each sentence is 'Already melting under the bright winter sun'. In the sentence 'Marcus began work on a giant snowman,' this participial phrase provides additional information about Marcus melting under the sun as he starts the task. In the second sentence, 'Julia brushed her teeth' is complete by the participial phrase 'after eating.' This phrase gives us more details about when Julia brushed her teeth. So, the correct answer is 'Julia brushed her teeth after eating'.
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