The phrase "to work a line" means to have a job or task that involves performing certain actions repeatedly or in a specific order, often as part of a production or assembly process.
Sentences with «to work a line»
A well - trained adult dog from working lines can be expected to be under command and continuously working for up to 45 minutes at a time. (samthedogtrainer.com)
Although degenerative joint diseases such as hip dysplasia are potential problems, they are relatively uncommon in working lines in the breed. (canismajor.com)