单项选择题
What are two steps that are taken when a router converts a voice signal from analog to digital form？（）
A. sampling B. packetization C. quantization D. serialization
多项选择题 Whichtwostatementsaretrueaboutvoiceportsonarouter？（）
多项选择题 WhichtwostatementsaretrueaboutthedigitalaudioinaVoIPnetwork？（）
多项选择题 Whichtwostatementsaretrueaboutanalogtodigitalconversionofvoicesignalsforuseindigitaltelephonynetworks？（）
