A．Store them in the filing cabinets.
B．Destroy them after the meeting.
C．Circulate them among the readers.
D．Read them from time to time.

A．Because it is convenient to carry and read.
B．Because it is very energy-saving.
C．Because it is a traditional way to carry information.
D．Because people seldom lose the information on paper.

A．It is recalled after a long time.
B．It is studied at all levels.
C．It is repeated again and again.
D．It is processed in the human mind.