11. Drinking this water is not safe. à It’s not ________________________________________________________________________ .
12. Swimming across this river is dangerous. à It is___________________________________________________________________________ .
13. To do this exercise is not easy. à It’s ___________________________________________________________________________ .
14. It is difficult to open the window. à To open____________________________________________________________________ à The window _______________________________________________
15. They are going to see a movie. à They will__________________________________ à They intend___________________________________
16. I ought to go and visit Grandma after work. à I have______________________________________________ à I must_____________________________________________