Challenging exercises Jaa Sulje 3/01. Exercise 1.19 Avaa lomake 3/01. Exercise 1.20 Avaa lomake 3/01. Exercise 1.21 Avaa lomake 3/01. Exercise 1.22 Avaa lomake 3/01. Exercise 1.23 Avaa lomake 3/01. Exercise 1.24 Avaa lomake