【简答题】加工中心的主轴上通常设有光电脉冲回转编码器,其作用是用来精确确定主轴回转的()。
【单选题】—The bus left five minutes ago.What should we do? —Well ,you can take the 2:00. —OK.Two tickets,please. —_________ —Round trip.
B.
One way or round trip?
【单选题】---I’m sorry you have missed the bus. It ______ just two minutes ago. ---What a pity!
【单选题】串s1=‘ABCDEFG’,s2=‘PQRST’,函数concat(x,y)返回x和y串的连接串,substr(s,i,j)返回串s的从序号i的字符开始的j个字符组成的子串,strlen(s)返回串s的长度,则concat(slabstr(s1,2,strlen(s2)),substr(s1,strlen(s2),2))=_________
【简答题】There were five apples in the basket two minutes ago. 变否定句: 变一般疑问句: 肯定回答: 否定回答:
【单选题】在同一枪位下,整个过程中TFe含量的变化主要取决于( )的氧化速度。