black band

• 菱铁矿,黑带,无火花换向区

black band的用法和样例：

例句

1. A karate black belt chopped my knee when I sparred with him.
   我和一个空手道黑带对打时，他砍了我膝盖。
2. The Six Sigma Black Belt will demonstrate the ability to read a fault tree.
   西格玛黑带应能示范其理解故障树分析的能力。