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: The database, he believes, has not physically disappeared as first thought.

SOLUTION: Singular

PROBLEM: Her aura, which moments before was clear and bright, was suddenly cloudy with a burst of mustard color.

SOLUTION: Singular

PROBLEM: Apparently the board members have been sharing what they knew about Elizabeth's fight for autonomy. "

SOLUTION:
Plural