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 trickle of something simmered in my gut and the buzz of anxiety spread.

A: Singular
****
Q: The deep boom of the two shots, which had been batting to and fro among the mountains, died away.

A: Singular
****
Q: The bruise formed three sides of the outline of a rectangle : top, side, and bottom.

A:
Singular
****