—Her concert was  ______ big successs last night.

—I think it surely makes ______ difference for a new talent.

A．不填；不填

B．a; a

C．a; the

D．a; 不填

改正用得不恰当的成语：当部队顺利通过横跨在深谷上的木板之后，首长命令立即拆除木桥，来了个过河拆桥，把尾随的敌人隔在了深谷的彼岸。