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: The tail rushed by and a loud thud followed.

A: Singular
****
Q: Her aura went muddy again and I watched her take a deep breath.

A: Singular
****
Q: The helmets use a simple tongue and key locking system.

A:
Plural
****