题目

答案：解：原式=133+1+1155+3+1357+5+⋯149×4749+47 =3-123+5-3215+7-5235+⋯49-47249×47 =121-13+13-15+⋯147-149=121-17=37. 故答案为：37.Faced with a bill for $ 10,000,          .       A．John has taken an extra job       B．the boss has given John an extra job       C．an extra job has been taken       D．an extra job has been given to John