Still waters run deep.
懂得潜水的人或许都有过这样的经验,就是愈平静的水面,海底反而更是波涛汹涌.英谚语有句叫Still waters run deep.（静水流深）,喻意凡事不可只看表面,也有‘大智若愚 / 智者慎言’的意思.或者可用There's more than meets the eye.（比眼看不见的还要多）/ Appearances can be deceiving.（外表是可以骗人的）,所以我们凡事不应以貌取人.