keep the door closed 是一个普通的词组，遵循语法造句就行了。祈使句如：Tom,please keep the door closed .
Tom,请让门一直关着。陈述句.如：We cannot keep the door closed to the outside world.
我们不能让通向外面世界的门一直关着。=我们不能闭关自守。一般疑问句如：can you keep the door closed ?
你可以让门一直关着吗特殊疑问句如：Why don't you keep the door closed?
你为什么不让门一直关...
