户枢不蠹

Explanation: Shu: door hinge; beetles: borers. Axis of rotation of the door often will not be moth-eaten. What metaphor regular exercise is not easy erosion. Often movements can also be used to keep fit 　　Usage: The main predicate; as subject, object; metaphor regular exercise can strengthen people 　　Source: Warring Lu Pu-wei "Lu give all": "Sweep creaking cricket, moving too." 　　Examples: "Water does not rot, ~," is that they are in constant movement of microbial or other biological resistance to erosion. (Mao Zedong, "On Coalition Government") Thesaurus:  Glide Not rot, door pivot immortalisation, Running water is never stale and a door-hinges never get worm-eaten, practice keep one always fit, Door pivot Not Gryllotalpa africona