backbonen.脊骨；骨干；骨气；毅力Backbone Network Service中枢网络服务backbone of college students大学生骨干Backbone resonance assignment主链指认backbone transmission network骨干传输网backbone network connectivity主干网络连接backbone wireless mesh networks骨干无线网状网backbones in subjects as experts专家型学科骨干backbone cyclorotation reposition脊柱旋转复位backbone deep muscles stability training脊柱深部肌肉稳定性训练

1. The main road is not clear until midnight.
   这条交通干道直到半夜才畅通无阻。
2. We've already cleared up the accumulated snow on the main road.
   我们已经清理了干道上的积雪。