When the length of a object is 1000mm,The drawing scale is 1:20 ,then the size we draw on the sheet should be
A. 100
B. 1000
C. 50
D. 20
Which one is not a basic solid
A. stairs
B. cyinder
C. prism
D. pyramid
The purpose of thin dashed dotted line is to
A. Represents an imaginary outline
B. Represents the visible outline
C. Represents invisible outline
D. Center line or axis
If the cutting plane of a cone is parallel of the base, the intersection line should be
A. circle
B. ellipse
C. rectangle
D. triangle
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