flatadj.平坦的；扁平的；单调的；断然的；[音乐]降音的；气不足的adv.平直地；直截了当；低于标准音高地n.<英>公寓；平面部分；[音乐]降半音；泄气轮胎v.变平；降调；住公寓flatwormn.扁形虫

1. The mathematical model of the hyperboloid twist drill was introduced.
   介绍了以旋转单叶双曲面作麻花钻钻尖后刀面的数学模型。
2. A twist drill is designed to drill a hole which has a particular size.
   麻花钻用来钻削具有一定尺寸的孔。