次摆线

例句：

1. 1. The secondary swing line is crucial for the stability of the system.
   次要摆动线对于系统的稳定性至关重要。
2. 2. The engineer used the secondary swing line to calculate the force on the beam.
   工程师使用次要摆动线来计算梁上的作用力。
3. 3. The secondary swing line was used to determine the optimal position for the anchor point.
   次要摆动线被用来确定锚点的最优位置。