The book which had a great influence on sociology was written ______.

A．groups, classes
B．degrees, standards
C．music, art
D．beginning, start

A．There are many kinds of amusements you can enjoy with spending no money.
B．The film shown at the local public library is often free of charge.
C．Local colleges often hold meetings to debate the issues people are interested in.
D．You should be a tourist if you want to know more about the city you live in.