TASK DEFINITION: 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.
PROBLEM: This huge upright mass did not, however, rise directly from the sea.

SOLUTION: Singular

PROBLEM: Like the trickling of a river, her race began to manifest and walk toward her.

SOLUTION: Singular

PROBLEM: Their meetings were completely innocent.

SOLUTION:
Plural