A Built-up Fixture on lathe的用法和样例：
- The speed of the car was reduced from 40 mph to 30 mph when entering a built up area.
- He has built up a good business over the years.
- One team has already built up a commanding lead.
- Acne is usually caused by a combination of factors including a build up of dead skin cells, excessive sebum production, and bacterial overgrowth.
- Ketoacidosis (high blood-glucose levels leading to a build up of ketones) is dangerous if untreated and needs emergency treatment.