单项选择题
A.Protel DOS Schematic Libraries.ddb B.Intel databooks.ddb C.Miscellaneous Devices.ddb D.Protel DOS Schematic TTL.LIB
A.Help B.Examples C.System D.Library
A.TopLayer顶层 B.Mechanical layer机械层 C.Silkscreen丝印层 D.BottomLayer底层