Final answer:
Each of the sentences 'My best friend eats ice cream.', 'My best friend plays basketball.', 'My best friend helps me with homework.', and 'My best friend lives next door.' are already complete, with 'My best friend' as the subject and the rest of the sentence as the predicate.
Step-by-step explanation:
Your question is to add a subject, predicate, or both to make these group of words a complete sentence. Let's see: 1) 'My best friend eats ice cream.' This sentence seems complete. The subject is 'My best friend' and the predicate is 'eats ice cream.' Similar is the case with 2) 'My best friend plays basketball.' 3) 'My best friend helps me with homework.' and 4) 'My best friend lives next door.' In each of these sentences, 'My best friend' is the subject and the rest of the sentence is the predicate, making them complete.
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