31.1

(1) I have to go hospital because I have bad cold.

(2) She has to study hard because the eaxm is comming.

(3) We didn't have time so we had to go back.

 

32.2

(1) You have to stand up the floor is dirty.

(2) I had to sleep late  becaue my sister made a noise.

(3) You don't have to go there.

(4) I didn't have to do that beacause my friends finshed that.