xīn / lǐ / yī / shēng / zhèng / zài / yán / jiū / shī / nüè / pǐ / de / chéng / yīn / hé / zhì / liáo / fāng / fǎ

心理医生正在研究施虐癖的成因和治疗方法。

The psychologist is studying the causes and treatments of sadism.