【判断题】气动换向阀的尺寸一般都比液压换向阀小是因为气体的粘度小,动作迅速。
【判断题】气动换向阀的尺寸一般都比液压换向阀小是因为气动系统的额定压力一般不超过1MPa。
【简答题】When Jack was very young, he played a lot of football and he was very 1 at it. But then he went and worked in a town and there was no team for him, so he stopped 2 .Then he began to get rather ...
【单选题】在默认情况下,在Eexcel2010单元格中输入公式并确定后,单元格中显示_____。