样条曲线中，顶点有几种类型。（）
A.BEZIERCORNER
B.BEZIER
C.CORNER
D.SMOOTH
参考答案：A, B, C, D
Mr. Black_____a telephone meeting when I got to his office yesterday afternoon.[ ]
A. has
B. had
C. is having
D. was having
设备管理“三好”指哪“三好”？（）
A、用好
B、管好
C、摆好
D、修好
