Math New Drill : Level 2 SNJ00-0801-L2 Put scale in stick to make ruler

By putting scales in three places on the stick of 9 cm in length, I want to measure all the length of 1, 2, 3, 4, 5, 6, 7, 8, 9 cm at once. 
Where do I mark three scales in A, B, C, D, E, F, G, H of the figure below? 
Answer all cases.














Answer
Four ways as shown below