preparing the classes

• 备课

preparing the classes的用法和样例：

例句

1. The teacher is preparing the lesson.
   老师在备课。
2. Redeye, because I never feel ready toteach no matter how late I stay up preparing.
   说熬红眼睛，这是因为我晚上无论备课到多晚，总觉得还不充分。