John thought that he would get a good grade if he could keep on the good side of the teacher.

他们很想在候德孙老师的班里取得好成绩。他们想尽办法来得到它。

Alan was always nice to his teacher, but I think he just wanted to butter her up to get a good grade.

亚伦对他的老师总是毕恭毕敬，但我觉得他只是想讨好老师以得到好成绩。