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\*.

Q: who is described as a shrewd and knavish sprite

A: Puck
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Q: which city is known as pearl city in india

A: Tuticorin (Thoothukudi)
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Q: a species that has an essential role in maintaining ecosystem structure is called a

A:
A keystone species
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