Plain 词形变化 Plains 复数 释义与例句 name 1. A surname. 相关短语 plain text 明码电文, 明语 [计] 纯文本 plain paper plain song plain sailing 平安航行, 一帆风顺 plain as the nose on one's face plain line plain and simple plain lines plain Jane 外表平凡的女孩子 plain Janes plain clothes n. 便衣, 便服, 便衣警察; 便装 plain lining plain lined plain flour n. 不含酸酵粉的面粉 Plain of Jars