S1: A common disease of the eye is conjunctivitis or ‘pink eye’, which often occurs in school-children. P: This disease spreads rapidly among school-children. Q: A white discharge also appears in the corners of the eyes. R: One or both eyeballs turn quite red and have a feeling of irritation. S: This discharge forms a crust which can often be seen in the morning after the eyes have been shut all night. S6: Students with this condition should be sent to the doctor. Find the correct sequence of P, Q, R and S.