Plans have been proposed ______ the largest dam in the world to be built along the Congo river.

A．of

B．with

C．for

D．on

锅炉停用的时间较长时，应将煤斗原煤烧尽，防止积煤（）。发现煤斗内的煤有自燃现象时，应即采取措施灭火。

A.坍塌

B.冒烟

C.自燃

D.过多