plain to对 ... 是清楚的
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 film examination腹部平片检查
Plain-headed Creepern.素头纹雀
plain equal side outet不带边同径二向三通
plain-end wheel drill两端装轮式普通条播机
plain labyrinth packing平齿型迷宫气封
Plain-crested Elaenian.纯色冠伊拉鹟