【判断题】在刀具角度中,主偏角影响刀具的锋利程度、减少切屑变形、减小切削力。
【单选题】To my surprise, he was lost in thought then and not ____ of my presence at all.
【单选题】I went to visit him, but _________, he left a minute ago. [ ]
【简答题】To my great surprise the food was still on the table, .