have feet of clay 潜藏的严重缺点
【讲解】
feet of clay 就是指“泥足"，例如：a colossus with feet of day (泥足巨人）。have feet of day字面指“有泥足”，喻义为“有潜藏的严重缺点”。
【对话】
A:Generally speaking, Francis is a very good student.
A:总的来说，弗朗西斯是个非常优秀的学生。
B:Yet she's also said to have feet of clay.
B: 然而据说她潜藏着严重的缺点。
A:What's that?
A:是什么呢？
B:She always refuses criticism and advice.
B:她总是拒绝批评和建议。
