Susie's mom bought her SOMETHING at the grocery store.
Vague nouns are unspecific things that don't tell you exactly what something is!
More examples of vague nouns: something, things, stuff, etc.
Adverb would be the correct answer
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Pandora's box: source of many troubles/problems
1) Possibly a car accident could lead to a Pandora's box of injuries and surgeries in the body.
2) If someone goes around spreading lies about a dangerous threat, it would cause many issues.