retaining nut

例句：

1. 1. The engineer retained the nuts to secure the bolts in place.
   工程师保留了螺母，以固定螺栓到位。
2. 2. The carpenter used a retractable hammer to retain the nuts without damaging them.
   木匠使用可缩回的锤子来保留螺母，而不损坏它们。
3. 3. The construction worker tightened the nuts on the bolts to ensure they would not come loose.
   建筑工人紧固螺栓上的螺母，以确保它们不会松动。