【单选题】Hi, Bob. How are you doing? It has been a long time _____ we left our junior middle school.
【判断题】党政机关的正文往往由若干个自然段组成,在书写时要注意空格。
【单选题】电路如图2所示,电压U等于( )。【图片】
【单选题】电路如图21所示,电压U等于( )。【图片】
【单选题】____ we are doing has never been done before.
【判断题】That we are doing has never been done before.
【单选题】_____ we are doing has never been done before.
【单选题】电路如图21所示,电压U等于( )。【图片】