OK, see, if you are blanking and don't remember the signs, then you can just draw this picture and make sure that you get it right.

这么看来，如果记不住负号的话，可以画个图再确认一下。

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New method of chemistry container connecting leg blanking was introduced, and got exact unfold picture by computer. The method is fast, exact and dependable.

介绍了化工容器连接管下料的新方法，借助于计算机得到精确的展开图，该法快捷方便，精确可靠。

youdao