In this task you are given a sentence. You must judge whether subject of the main clause is singular or plural. Label the instances as "Singular" or "Plural" based on your judgment.
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Question: A mass of recruits had already gravitated to the Whites.

Answer: Singular


Question: In the time it took to answer, several galaxies unfolded, whirled around Azrael like paper streamers, impacted, and were gone.

Answer: Plural


Question: Ivar the Viking leader gave a harsh whisper to be quiet while he was surveying the river ahead.

Answer:
Singular