The following passage consists of six sentences. The first and the sixth sentences are given in the beginning. The middle four sentences have been removed and jumbled up. These are labeled P, Q, R, and S. You are required to find out the proper sequence of the four sentences.
S1: Two men held a struggling crazed dog down on a table.
S6: The men watched him awestruck.
P: Its mouth was smothered with saliva and a bite from its jaws might cause death.
Q: He put one end of the tube between his lips and lowered the other towards the foam covered jaws.
R: Beside them stood Louis Pasteur holding a narrow glass-tube in one hand.
S: As the animal writhed he carefully sucked some of the saliva up the tube.
The proper sequence should be
PRQS is the correct option.