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: the reciprocal (inverse) of the period of oscillation is

A: Frequency
****
Q: who built the kaaba stone according to the quran

A: Ibrahim and Ishmael
****
Q: what year was under god added to the pledge of allegiance

A:
1954
****