What should the students do when s teacher or a visitor goes into the room?

stud what should we do___ the poor men what should I protect the wildlife What letter should replace the question mark. 【what he should do with the 英语翻译What is the maximum number of wire terminals that may be stacked on a single stud in a terminal strip? What should we do to protect the environment we should do what we can protect the environment改错 What should we do to save the earth?是什么时态 What should you do when you cross the road?回答 if you have the Swine Flu,what should you do What letter should be in the place of 翻译；What should he do before he takes the taxi. What should we do?when we have the fever What face should be in circle Please drase draw the what should we do before we c_____ the road. what number should be in the place of?? My bag_____(leave) is the taxi.What should i do?