工件以平面定位时,所用的定位元件可采用()。
A.V形块
B.螺栓
C.削边销
D.支承钉
参考答案:D
—I couldn’t get through to you at home last night. You must have gone out then, ________?
— Yes, I went to the cinema.
A.mustn’t you
B.haven’t you
C.can’t you
D.didn’t you
Applet生命周期方法有init(),______(),stop()和destroy()。