Robbins Manufacturing produces a variety of plastic containers using an extrusion blow molding process.

Classify each of the following activities that are part of Robbins Manufacturing's operating process as either unit$-$level, batchlevel, product$-$level, or facility$-$level.

$\backslash$table$[[1.,$Patents are obtained for each new type of container mold.,Product$-$level$],[2.,$Each type of container has its own unique molds.,Product$-$level$],[3.,$Routine maintenance is performed on the extrusion machines.,Facility$-$level$],[4.,\backslash$table$[[$The sales force incurs travel expenses to attend various trade shows throughout the$],[$country to market the containers.$]],$Facility$-$level$],[5.,$Plastic resins are used as the main direct material for the containers.,Unit$-$Level$],[6.,$The extrusion machine is calibrated for each batch of containers made.,$],[7.,$A plant manager oversees the entire manufacturing operation.,$],[8.,$Rent is paid for the building that houses the manufacturing processes.,$],[9.,$Each container product line has a product line manager.,$],[,$Each container is cut from the mold once the plastic has cooled and hardened.,$]]$