Which of these machines work on the same principle as does the see-saw?
A P and Q
B Q and R
C P and R
D R and S
Which of these machines work on the same principle as does the see-saw?
A P and Q
B Q and R
C P and R
D R and S
Which of these machines work on the same principle as does the see-saw?
A P and Q
B Q and R
C P and R
D R and S