Using a minus sign before a keyword search indicates that a. you're adding a "+" and then a "-"to refine the search. b. it's an optional term within your search. c. you're adding a word to your search. d. the word following the "-" is to be excluded from search.

Each container is cut from the mould once the plastic has cooled and hardened. unit-level 2 patents are obtained for each new type of container mould. facility-level 3. plastic resins are used as the main direct material for the containers. product-level 4. a plant manager oversees the entire manufacturing operation. facility-level 5. the sales force incurs travel expenses to attend various trade shows throughout the country to market the containers. product-level 6. each container product line has a product line manager. product-level 7 the extrusion machine is calibrated for each batch of containers made. facility-level 8. each type of container has its own unique moulds. unit-level 9. routine maintenance is performed on the extrusion machines. facility-level 10. rent is paid for the building that houses the manufacturing processes. classify each activity as either unit-level, batch-level, product-level, or facility-level.