第一个模型是画在白板(或者一沓纸)上的，一般不那么正规。
The first models are drawn on the whiteboard (or on a sheet of paper) and tend to be informal.
一沓卡片上是我要记的有机化合物的名字和定义，看起来没个尽头。
One stack had the names and definitions of the seemingly endless number of organic compounds I had to memorize.
建模的过程可以从传奇般的餐巾纸(一块白板或者裁好的一沓纸是很好的替代品)上的系统草图开始。
The modeling process may start with a sketch of a system on the legendary napkin (a white board or a regular sheet of paper are good alternatives).
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