plainlyadv.清晰地；明显地；直截了当地；朴素地plainadj.清楚的；简单的；坦白的；平常的；朴素的；纯的n.平原；广阔的区域adv.完全地；纯粹地plain-laid rope三股左旋绞绳plain equal cross不带边同径四通plain end of pipe管子的平端plain steel-bar光面钢筋plain blank board无空白模件板plain cornerjoint平头角焊接plain pearl gauze素珍珠罗plain satin shoes素缎鞋plain round steel普通圆钢plain radiography平片X线摄影(术)