The telephone (from the Greek: t??e, tele, "far" and f???, phone, "voice") is a telecommunications ___________ that is used to transmit and receive sound (most commonly speech), usually two people conversing but occasionally three or more.
device
technologies
profession
It is one of the ________ common household appliances in the world today.
more
most
popular
Most telephones operate through transmission of electric signals over a complex telephone network _________ allows almost any phone user to communicate with almost anyone.
where
whose
which
A traditional landline telephone system, also known as "plain old telephone service" (POTS), commonly _________ both signaling and audio information on the same twisted pair of insulated wires: the telephone line.
handles
obstacles
separates
___________ originally designed for voice communication, the system has been adapted for data communication such as Telex, Fax and Internet communication.
Since
Because
Although
The signaling equipment ______________ a bell, beeper, light or other device to alert the user to incoming calls, and number buttons or a rotary dial to enter a telephone number for outgoing calls.
consists of
have
possess
A twisted pair line is preferred as it is more effective at rejecting electromagnetic interference (EMI) and crosstalk than an ____________ pair.
twisting
twisted
untwisted
A calling party wishing to speak to another party will pick up the telephone's handset, thus operating a button switch or "switchhook", which puts the telephone into an active state or "off hook" ________________ the transmitter (microphone), receiver (speaker) and related audio components to the line.
by connecting
not connecting
if connecting
This circuitry has a low resistance (less than 300 Ohms) ________________ DC current (48 volts, nominal) from the telephone exchange to flow through the line.
and
which causes
that produce
The exchange detects this DC current, ________ a digit receiver circuit to the line, and sends a dial tone to indicate readiness.
to attach
attaches
attaching