The following six sentences come from a paragraph. The first and the last sentences are given. Choose the order in which the four sentences (PQRS) should appear to complete the paragraph.
S1. American private lives may seem shallow.
P. Students would walk away with books they had not paid for
Q. A Chinese journalist commented on a curious institution: the library
R. Their public morality, however, impressed visitors.
S. But in general they returned them.
S6. This would not happen in China, he said