单词back clearance
un.: 背隙;活塞与活塞圈间径向间隙网络: 后部余隙;活塞和活塞环间径向间隙;背面裂隙
活塞与活塞圈间径向间隙
背隙
But those who back clearance enterprise can compare to the early through.
但是那些进行提前清关的企业能够比较早地通过。