总平面图是画在有等高线或坐标方格网的地形图上。

多项选择题An alien spacecraft is flying overhead at a great distance as you stand in your backyard. You see its searchlight blink on for 0.190 s. The first officer on the spacecraft measures that the searchlight is on for 12.0 ms. Which is the right statement about the measurement? A、The time of 0.190 s measured by you is the proper time. B、The time of 12.0 ms measured by the first officer on the craft is the proper time. C、The proper time is smaller than 12.0 ms D、Based on these measurements, the speed of the spacecraft can be calculated.

单项选择题工程图中图线有粗、中、细之分，只要是轮廓线都用粗线绘制。