Answer:
main character is (S)
his intelligence is (S)
he begins (S)
buzzer sounds (S)
sounds of bells, sirens, and other awful noises (P)
his intelligence remains (S)
conflict begins (S)
memories quickly escape him, they linger, and haunt him (P)
they (S)
Singular subjects: 7
Plural subjects: 2 (sounds of bells, sirens, and other awful noises; memories, they)