一门课 yī mén kè — a course; a subject

Definitions

1. a course; a subject

Examples

• 这学期我选了三门课，其中一门课是古代汉语。

  I took three courses this semester, one of which was classical Chinese.

• 他这学期选修了一门课，叫逻辑学。

  He elected a course this semester called logic.