25.填空 良药苦口 ___ ___ ___ 。 - Cchatty

良药苦口利于病（lìyúbìng），忠言逆耳利于行。Good medicine is mostly bitter, but it is good for curing diseases; Most of the language that teaches people to be good is not very beautiful, but it helps people to correct their shortcomings.

良药苦口利于病 - good medicine for health taste bitter to the mouth