what does it mean?it means you should stay ____from it.(一个危险标志)
it means you shouldn't ____ here.（禁止吸烟的标志）
it means you _____keep _____in the hospital.（禁止喧哗的标志）
it means you _____walk _____ _____ _____.（禁止踩草坪的标志）
顺便都翻译一下
再翻译一个：what does this sign mean?