关于must的否定1.You must switch off the lights.(该为否定句)You _______

关于must的否定1.You must switch off the lights.(该为否定句)You _______ You must pick the flower(否定句) you must wait for the green light .改为否定句 You must eat in the classroom 改为否定句 (you must cross the strees )怎么改为否定句 You must stop at the red light变成否定句 you must pick the flowers改为否定句 You must pick the sunflowers.(改为否定句） You must wait.(怎么改否定句) You must stop.改成否定句 You must wear uniforms.改否定句 You must turn off your cell phone when you take a plane改为否定句