Mark Twain worked for several years as a pilot on a steamboat, taking passengers up and

down the Mississippi, the great river ___flows from the north of the US near the Canadianborder.

A．as

B．what

C．which

D．who

毛 * * 思想活的灵魂包括（）。

A.群众路线

B.实事求是

C.独立自主

D.为人民服务