1. 用所给单词的适当形式填空

1. （1） He is(worry /worried) about the maths exam  

3. （2） It's(danger / dangerous ) to smoke too much
   

5. （3） Tom lives on the (nineteen / nineteenth ) floor . It's too high , so he has to take a lift every day  
   

7. （4） We should get about eight (hours' / hour's ) sleep every day
   

9. （5） Your room is o dirty . It requires (cleaning / cleaned )