the isometric projection of a profile circle is an ellipse. the minor axis of the ellipse is in coincidence with , and the major axis of the ellipse is perpendicular to .
采样过程从物理意义上可以理解为()。
将连续信号通过采样开关变换成()的过程称为采样过程。
在书写原电池符号时,相接面之间要用逗号隔开,同一相不同的离子之间用竖线隔开。
which options belong to the five important screw thread elements?
the methods which can be used in representing machine parts, include regular views, sectional views, removed sections, and the like, which can also be used to represent assemblies.
in using autocad software, when the command mirror is used, the mirror line must be center lines.
if a line is an oblique line, the projections of the line will be foreshortened lines in the three planes of projections.