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: Still, there was a certain subtlety of expression that Earth models lacked'.

SOLUTION: Singular

PROBLEM: A swift rap on the rump with a rolled-up newspaper works for me. "

SOLUTION: Singular

PROBLEM: The technicians swallow their doubts and start getting me ready again.

SOLUTION:
Plural