A damp foundation stone indicates impending rain; it signifies that one can foresee future developments by observing subtle early signs.
看到他最近学习状态很好，常常主动请教老师，这真是础润而雨，预示着他这次考试一定能取得好成绩。
Seeing his excellent study habits lately, often proactively asking teachers for help, this is a clear sign, predicting he will surely achieve good results in this exam.
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