To have some milk before going to bed is good.（用it作形式主语）怎么写

To have some milk before going to bed is good.（用it作形式主语）怎么写 It's good for your （） to wash your feet before going to bed it作形式主语怎么用?it+is+adj.+to+v. Before -------(go) to bed,he needs ----(drink) some milk. It’s a good habit of to read a few lines before going to bed Before -------(go) to bed,he needs ----(drink) some milk.怎么填 It's good for people____ before going to bed.A.walk B.walkin To swim in this river is very dangerous(用IT作形式主语改写句子） We have to finish all the work before going to bed（）（）? Put out the fire before going to bed.这句话before后面省略了主语,可是前面用的 Singing English songs is a good way to learn English用it作形势主语 To keep in good health is very important.用it作主语改为同义句