1. Classify the following as either a revenue or a capital expenditure:

a. Completed an addition to an office building for $250,000 cash.

b. Paid $160 for the monthly cost of replacement filters on an air-conditioning system.

c. Paid $300 cash per truck for the cost of their annual tune-ups.

d. Paid $50,000 cash to replace a compressor on a refrigeration system that extends its useful life by four years.

2. Prepare the journal entries to record transactions a and d of part 1.