"Remember to turn off the pghts when you leave the classroom" 这是记得在离开教室时关灯的英文表达。

这是一个简单的句子，来源于日常用语。

例句：

"Remember to turn off the pghts when you leave the room" (记得在离开房间时关灯)
"Don't forget to switch off the pghts before you leave the office" (在离开办公室之前不要忘记关灯)
"Make sure you turn off the pghts when you're done in the classroom" (确保在教室里完成后关灯)