Our village carpenter (木匠) ,John Hill,came one day and made

Our village carpenter (木匠) ,John Hill,came one day and made a dining table for my wife.He made it just the right size to be put into the place between the two windows.When I got home that evening,John was drinking a cup of tea and writing out his bill (账单) for his job.
My wife said to me,quietly,“That’s his ninth cup of tea today.” But she said,in a loud voice,“It’s a beautiful table,dear,isn’t it?”
“I’ll give him money for his work when I see the bill.” I said.
John laughed and gave me his bill for the job.I read:
One dining table 10 November 1999
Cost of wood (木材成本) $ 17.00
Paint（油漆） $ 1.50
Job,8 hours ($ 1 an hour) $ 8.00
Total (合计) $ 36.50
When I was reading his bill,John said,“It is a fine day,isn’t it?Quite sunny.”
“Yes,” I said.“I’m glad it’s the 10th of November.” “Me,too,” said John.“You wait – it’ll be a lot colder by the end of the month.”
“Yes.Colder – and more expensive (昂贵)!Dining tables will be $20 more expensive on November 30th,won’t they,John?”
John looked hard at me for half a minute.Was there a little smile in his two blue eyes?I gave his bill (
How much would john sak for if he made a dining table on the last day of December according to his bill?
A.$26.50 B.$ 36.50 C.$56.50 D.$57.50
为什么选择D.

Cost of wood (木材成本) $ 17.00
Paint（油漆） $ 1.50
Job,8 hours ($ 1 an hour) $ 8.00
Total (合计) $ 36.50
总计：17.00+1.5+8.00=26.50 John是把号数10加上了,所以他算出36.50.十二月大,有31天,按John的计算,26.50+31结果是57.50,当然就选D