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.

[Q]: A mass of recruits had already gravitated to the Whites.
[A]: Singular


[Q]: The concepts formed a vague semi circle around Fate, only Irony grumbled about it.
[A]: Plural


[Q]: As he watched Craig and Anna for a moment through their craft's windshield -- kissing passionately, the pilot grinned with relief.
[A]:
Singular