mull technique

例句：

1. 1. This is a crucial skill that needs to be mastered for success in the field.
   这是一项关键技能，需要掌握才能在领域取得成功。
2. 2. The engineer used mull technique to improve the efficiency of the machine.
   工程师使用磨砺技术来提高机器的效率。
3. 3. The company has been refining its mull technique over the years to stay ahead of the competition.
   该公司多年来一直在磨砺其技术，以保持在竞争中的领先地位。