故而

dǎo shī biàn zhèng zhǔn què xuǎn fāng yòng yào jīng dàng gù ér liáo xiào xiǎn zhù yào dào bìng chú

导师辨证准确，选方用药精当，故而疗效显著，药到病除。

Instructor dialectical accurate, precise and appropriate selection prescription, and therefore a significant effect, to cure the patient.