The key
Exercise 1
1. go, are going
2. have lost
3. knows, is talking, makes
4. knows, are disappearing
5. have you done
6. have you seen, is staying, is being
7. are becoming
8. isn’t working, has taken
9. rises, sets
10. gives
11. are getting
12. is playing, have never seen
13. is playing, knows
14. are you doing, are you lying, haven’t I told
15. is selling, do you know, wants
16. am getting
17. is playing, haven’t heard
         Exercise 2
            1.    waters-is watering – has already watered
            2.    have just arrived- have you ever been-is
            3.    always produce
            4.    do you not eat-are you-don’t eat-prefer
            5.    has already baked-have tasted
            6.    do you smell
            7.    seems
            8.    understand
            9.    are you thinking
            10.   always want
            11.   acts-always was-have you ever seen
            12.   have you ever been
            13.   am working
            14.   is normally-are having
            15.   has found
            16.   looks-has passed
            17.   have painted
            18.   is arriving-Is everything-is
            19.   havent booked-are looking