Question

D.
15 hertz
C. 85 hertz
E. None of these
19. Which one of the following can conduct electricity?
A. A solution of salts
B. A solution of acids
C. A solution of bases
D. All of these
E. None of these
20. The image of an object seen by our eyes persists
on the retina for even after the object has
disanneared from our view,​

Answer 1

Answer:

all of these is the correct answer