下课了,同学们再见用英语怎么说

"Class is dismissed, goodbye students" is the most commonly used phrase to say "下课了,同学们再见" in English. The phrase "class is dismissed" comes from the military and educational context, it means the end of a class or lecture and the students are released or dismissed.
Example:
"Class is dismissed, see you all next time." (课程结束了，下次再见)
"Ok, class is dismissed for today. Have a great weekend!" (好了，今天的课结束了，周末愉快!)
"The bell just rang, class is dismissed. Don't forget your homework!" (铃声响了，课程结束了，不要忘了作业!)