翻译：务必在离开教室之前关掉所有的灯.(do+v.)
问题描述：
翻译：务必在离开教室之前关掉所有的灯.(do+v.)
答
Please do make sure you have switched off all the lights before leaving the classroom.
答
Make sure that you will turn off all the lights before leaving the classroom.
答
Do turn off all the lights before leaving the classroom!
答
Please switch off all lights before leaving the classroom.