【单选题】— _____ do you play tennis? — I play three times a week. [ ]
【单选题】A: - do they play football. B: -- Always.
【单选题】数控机床可以进行螺纹加工,是因为该车床安装了()。
【单选题】— did he play soccer? — About 15 years.
【判断题】在磨削过程中,当被磨表面出现波浪振痕或表面粗糙度值Ra增大,则表明磨粒已经变钝,锋利程度明显下降。
【单选题】--___ ___ do you play sports? --Twice a week.
【单选题】― do you play football? ―Once a week.
【单选题】快速鉴别橄榄石与黄绿色电气石戒指,不用下列哪种仪器
【单选题】---- _____ do you play football? ---- Once a week.
【判断题】数控车床可以进行螺纹加工,是因为该机床安装了光栅。