In this task, You are given an open-domain question that can be answered based on factual information. Your task is to provide \*short\* answer (in a few words only) for the given question. The short answer can be one or more entities or it can also be boolean \*yes\* or \*no\*.
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Question: which metal is used as a thin film on sweets

Answer: silver


Question: when did drinking age go from 18 to 21

Answer: mid-1988


Question: what is absolute zero on the celsius temperature scale

Answer:
−273.15°