subject and object

例句：

1. 1.The teacher asked the students to present their research on the subject of ecology.
   老师要求学生们就生态学这个课题进行汇报。
2. 2.The student's performance was a subject of discussion in the class.
   学生的表现是课堂上讨论的焦点。
3. 3. The scientist conducted experiments on different subjects to test his hypothesis.
   科学家在不同的科目上进行了实验，以测试他的假设。