HDLC中常用的操作方式不包括()。
A、正常響應方式C
暫無解析
Wecanhear____fromthebackoftheroom.
_____enoughtimeandmoney,theresearcherswouldhavebeenabletodiscovermoreinthisfield.
Thebackgardenofourhousecontainsalawn，（）verypleasanttositoninsummer.
Thecountry’schiefexportsarecoal,carsandcottongoods,cars_____themostimportantofthese.
Time_____,thecelebrationwillbeheldasscheduled.
