Why was the world market important for the United States agriculture

A．It provided evidence that Jefferson’s ideal could be achieved.

B．It made farmers less dependent on local bankers.

C．It affected the prices that farmers could receive for their crops.

D．It decreased the power of the railroads to control farm prices.

业务平台网管中心（含操作维护中心、互增中心）应实行（）小时值班。

A.5×8

B.7×24

C.5×24

D.7×8