ADSL通常采用三种基本的调制技术ITU、TG.992.1建议采用（）的调制技术。
A.QAM
B.DMT
C.VBS
D.CAP
参考答案：A
— When did the computer crash?
— This morning, while I ______ the reading materials downloaded from some websites. [ ]
A. have sorted
B. was sorting
C. am sorting
D. had sorted
阳地植物
