加工程序段出现G01时，必须在本段或本段之前指定（）之值。
A.R
B.T
C.F
D.P
参考答案：C
钢管按生产方法分为：有缝钢管和（）钢管
A．直缝焊
B．螺旋焊
C．无缝
D．异型
24. Because there was a conflict of interests among the leaders, two members ______ from the board of MVP in protest against its disharmony last week.
A．ranged
B．refreshed
C．resigned
D．Rejected
