A.60m,120m,250mB.60m,150m,250mC.80m,120m,250mD.80m,150m,250m
A.跟踪某条与时间相关的曲线B.跟踪空间某特定曲线C.以上都不是
A.6mm,6mmB.6mm,15mmC.6mm,25mmD.25mm,25mm