5 sentences

1. 他在高中选修了理科。

   tā zài gāo​zhōng xuǎn​xiū le lǐ​kē.

   He chose the science track in high school.

   Source: Dong Chinese Dictionary

2. 他在大学期间选修了量子力学。

   tā zài dà​xué qī​jiān xuǎn​xiū le liàng​zǐ lì​xué.

   He took quantum mechanics as an elective during university.

   Source: Dong Chinese Dictionary

3. 这学期我选修了一门遗传学课程。

   zhè xué​qī wǒ xuǎn​xiū le yī mén yí​chuán​xué kè​chéng.

   I'm taking a genetics course this semester.

   Source: Dong Chinese Dictionary

4. 医学生这学期需要选修组织学和胚胎学。

   yī​xué​shēng zhè xué​qī xū​yào xuǎn​xiū zǔ​zhī​xué hé pēi​tāi​xué.

   Medical students need to take histology and embryology as electives this semester.

   Source: Dong Chinese Dictionary

5. 他在大学期间选修了一门关于柏拉图的哲学课。

   tā zài dà​xué qī​jiān xuǎn​xiū le yī mén guān​yú Bó​lā​tú de zhé​xué kè.

   During his time at university, he took an elective philosophy course on Plato.

   Source: Dong Chinese Dictionary