DiffServ是Internet实现QoS的一种方式，它主要依靠______，其主要缺点是______。

A．RSVP和PATH
B．SLA和PHB
C．LSR和RTP
D．RESV和FEC

_________ different colors is their full-time job.

A．Dyeing cloth

B．Dyeing cloth into

C．Dying cloth

D．Dying cloth into