Last year, a certain public transportation system sold an average (arithmetic mean) of 41,000 tickets per day on weekdays (Monday through Friday) and an average of 18,000 tickets per day on Saturday and Sunday. Which of the following is closest to the total number of tickets sold last year

A．1 million

B．1.25 million

C．10 million

D．12.5 million

E．(E) 125 million

传动按工作原理可分为（）。

A.机械传动

B.流体传动

C.啮合传动

D.电传动