A.To emphasize the dangers of the old method.B.To explain a step in the new technique.C.To show that the treatment will not cause fire.D.To illustrate a combination of old and new treatment.
A.To emphasize the dangers of the old method.
B.To explain a step in the new technique.
C.To show that the treatment will not cause fire.
D.To illustrate a combination of old and new treatment.