Mortarboard/ Square academic cap, 學位帽/ 四方帽

Hebei, China
Children in gowns and mortarboards run during a kindergarten graduation ceremony in Handan
Photograph: China Daily/Reuters
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Mortar Board - Wikipedia

mortar-board - 學位帽 - 國家教育研究院雙語詞彙

Square academic cap - Wikipedia

四方帽