| Our
Model J251 Optical Demontration Case is a kind of combined teaching
aid for de- |
| monstration.
It can be used for primary school pupils to observe the straight
travel of light, |
| hole
image-forming, reflection & refration of light beam,
conver gence and divergence of |
| light
by lens,and image magnifying by convex lens in their classes
of knowledge of natural |
| science.
It can also be used to help pupils perform experiments in groups
or develop their |
| scientific
and technological activities. |
