Finish the sentence, gym is to healthy as book is to ?

"in my opinion, we ought to stop making our own drums and accept that outside supplier's offer," said wim niewindt, managing director of antilles refining, n.v., of aruba. "at a price of $21 per drum, we would be paying $4.70 less than it costs us to manufacture the drums in our own plant. since we use 70,000 drums a year, that would be an annual cost savings of $329,000." antilles refining's current cost to manufacture one drum is given below (based on 70,000 drums per year):