Ball mills are commonly used in the mining industry to grind ore into fine particles.

Degree mills are institutions that offer fake degrees.

The farmers used fanning mills to separate the grain from the chaff.

There are several flint mills in the area.

There are many gin mills in this neighborhood.

The gossip-mills were working overtime with rumors about the celebrity couple.

The pebble mills are used in the mining industry to grind ores.

There are several post mills in the countryside.

Roller mills are commonly used in the milling industry.

The roll mills are used in the manufacturing process.