【单选题】– I didn’t see you at the meeting yesterday. Why? Because I ______ for an important telephone at that moment.
【单选题】–Wait for a moment, please. I _______ the answer for you. –Ok, thank you very much.
【单选题】孔系组合夹具主要元件表面为圆柱孔和螺纹孔组成的 ( ) 孔系,通过定位销和螺栓来实现元件之间的组装和紧固。