Methods Lead levels were measured for 44 samples of stationery and 43 samples of drinks with government standard method.
2
本发明是压板，属于防止写字时本子卷边的文具技术领域，解决小学生写字时本子卷边的问题。
The present invention relates to a paperweight board, belonging to the field of stationery technology, aimed at preventing exercise-book edge from curling when schoolchild writes on it.
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