【单选题】He has been on Sam and John______ with me for 17 years.
【单选题】Sorry,he is out.He has been on vocation recently(最近).
【单选题】从钢琴改编曲《山丹丹开花红艳艳》和声上看,其中的引子部分是由一整段的琶音和弦构成,主要旋律是民族器乐 独奏,隐藏在这些分解和弦中,具有民族五声风格。这些分解和弦模仿 奏法。
【单选题】He has been on _______ missions. Nobody knows where he is.