a$.$

Straight$-$line depreciation on a building b$.$ Maintenance costs at a hospital c$.$ Rent on a photocopy machine charged as a fixed amount per month plus an additional charge per copy d$.$ Cost of goods sold in a bookstore e$.$ Salaries paid to temporary instructors in a college as the number of course sessions varies f$.$ Lumber used by a house construction company g$.$ The costs of operating a research department h$.$ The cost of hiring a dance band for three hours i$.$ Laser printer paper for a department printer j$.$ Electric power in a restaurant