back-up roll arbor

例句：

1. 1. The engineer used the back-up roll arbor to repair the damaged machine.
   工程师使用备用卷轴来修理损坏的机器。
2. 2. The construction crew had to rely on the back-up roll arbor during the rainstorm.
   在暴风雨期间，建筑工人不得不依赖备用卷轴。
3. 3. The scientist used the back-up roll arbor to test the new drug's efficacy.
   科学家使用备用卷轴来测试新药的有效性。