(2013·江西九江二模)If you won't do as I tell you, you get the chance to be promoted because the petition is just too fierce.
A. couldn't
B. mustn't
C. shouldn't
D. shan't
网友回答
A. couldn't
B. mustn't
C. shouldn't
(答案→)D. shan't
解析：选D 考查情态动词。句意：如果你不照我说的做，你就得不到晋升的机会，因为竞争太激烈了。shall用于第二、三人称可表示说话人给对方的警告，符合句意。