在三坐标测量机上直接实现对工件进行测量的部件是（）。
A.工作台
B.导轨
C.测头
参考答案：C
If I had met our Math teacher, I ______ him about the problem. [ ]
A. would ask
B. would have asked
C. asked
D. must have asked
对管道及其附件的严密性进行水压试验时，试验压力应等于管道工作时的压力。
