retaining ring lip

例句：

1. 1. The surgeon used a retractor to keep the patient'smouth open during the surgery.
   外科医生使用拉钩使病人的嘴巴张开以便进行手术。
2. 2. The artist carefully painted the retainingring lip on the sculpture to enhance itsbeauty.
   艺术家仔细地在雕塑上绘制了保持环唇，以增强其美感。
3. 3.The retaining ring lip was designed toprevent the tooth from shifting during chewing.
   保持环唇的设计是为了在咀嚼时防止牙齿移位。