Be s＿ to close the windows before you leave the classroom

Be s＿ to close the windows before you leave the classroom Be ----to close the windows before you leave. Close the windows before you leave the classroom.为何Close用原型, ___the windows before you leave the classroom. ---------(close)the windows before you leave the classrom. ------the windows before you leave the classroom.(please),谢了 Don't forget to close all the windows before you leave the c Students__________ to close the windows before they leave th Before you leave the classroom,please r____to close the wind I____(close)the windows before I leave. R____ to close the windows when you leave. Could you be so kind as to close the windows?