用光学分度头逐次测量外花键各键同一侧,可测出Z个差值,在Z个差值中,最大差值为()。
A.等分差值
B.中心夹角误差
C.累积误差
D.相邻误差
参考答案:A
–Why, Jack, you look so tired!
--Well, I ___the house and I must finish the work tomorrow.
A.was painting
B.will be painting
C.have painted
D.have been painting
4的算术平方根是( )
A.2
B.-2
C.±2
D.16