| 摘要 |
PURPOSE: An anti-slipping ruler is provided to prevent a ruler from slipping when schoolchildren draw lines using the ruler. CONSTITUTION: An anti-slipping ruler comprises a body, a scale unit and fixed grooves(5,7). The body has a fixed length. The scale unit is formed on one side of the body. Scale for measuring length is inscribed or printed on the scale unit. The fixed grooves are formed on the body. The fixed grooves can prevent slipping.
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