为什么下面的房间用the room below 下面的表格用the below form

1.the room below = 对!(The room below is for students only)
2.the below form = 不对!(口语:Please take the below form.../Hello,the below form is a consent of spouse form,i need to sign;Use the below form to reset your password.To reset your password,enter your email ...)
3.the form below = 对!(Please fill out the form below.../Now you can embed the comment form below the blogger post.)
4.below the form = 对!(Can I type anything "below the form"?/Can validation errors be displayed below the form?)