 
 <translate> Ball bearings are used in moving parts. Machines generally have moving parts.
So, the answer is machines. <ibo> A na-eji ihe ndị na-agba bọl eme ihe n'akụkụ ndị na-agagharị agagharị. Ngwá ọrụ na-enwekarị akụkụ ndị na-agagharị agagharị. Ya mere, azịza ya bụ ígwè ọrụ. 