Challenging exercises Jaa Sulje 3/04. Exercise 4.19 Avaa lomake 3/04. Exercise 4.20 Avaa lomake 3/04. Exercise 4.21 Avaa lomake 3/04. Exercise 4.22 Avaa lomake 3/04. Exercise 4.23 Avaa lomake 3/04. Exercise 4.24 Avaa lomake 3/04. Exercise 4.25 Avaa lomake