线上课是线下课的有益补充用英语怎么说

"Online classes are a useful supplement to offline classes" 是一个适用于表达“线上课是线下课的有益补充”的英文短语。这个短语主要来源于现代教育技术和在线学习的普及。

例句1:
"Online classes have become a useful supplement to traditional in-person classes, allowing students to access course material and lectures at any time."
（翻译：线上课已经成为传统面授课程的有益补充，学生可以在任何时间访问课程材料和讲座。）

例句2:
"I find that online classes are a great supplement to my offline classes, they provide me with additional resources and flexibility to learn at my own pace."
（翻译：我发现线上课是我线下课的很好补充，它们给了我额外的资源和学习自己节奏的灵活性。）