1.3-3 Packet switching versus circuit switching (2).  Which of the characteristics below are associated with the technique of circuit switching? Select all correct answers. [Hint: more than one of the answers is correct].多项选择题

Resources are used on demand, not reserved in advance.

Data may be queued before being transmitted due to other user's data that's also queueing for transmission.

Frequency Division Multiplexing (FDM) and Time Division Multiplexing (TDM) are two approaches for implementing this technique.

Congestion loss and variable end-end delays are possible with this technique.

This technique was the basis for the telephone call switching during the 20th century and into the beginning of this current century.

Reserves resources needed for a call from source to destination.

This technique is used in the Internet.