outer track

• 外圈； 外道

outer track的用法和样例：

例句

1. One integral flange on the outer ring and one loose flange ring.
   外圈带一个整体式法兰和一个松配合法兰圈。
2. In the meantime the outer pincers had met and closed.
   同时，外圈钳形围攻的部队已经会师合围。