A modem modulates a standard analog signal called a ____ wave so that it encodes binary information.

Under UNIX, you can print or display your working directory by issuing the line command __________.

a. dir b. ls c. wdir d. pwd

At regular intervals the AP sends a ____ frame to both announce its presence and to provide the necessary information for other devices to join the network.

A. master B. beacon C. data D. control