MIDI enables people to use （66） computers and electronic musical instruments. There are actually three components to MIDI, the communications " （67） ", the Hardware interface and a distribution （68） called "Standard MIDI Files". In the context of the WWW, the most interesting component is the （69） Format. In principle, MIDI files contain sequences of MIDI Protocol messages. However, when MIDI Protocol （70） are stored in MIDI files, the events are also time-stamped for playback in the proper sequence. Music delivered by MIDI files is the most common use of MIDI today.

67（）

A．device

B．protocol

C．network

D．controller

国际上汽车售后市场的经营模式有两种最具代表性，即（）

A.3S和4S

B.独家经营和连锁经营业

C.专场经营

D.4S和连锁经营