opaque, illumination, optic fibers , laser rays, beam of light
[1] Doctors use.............................to treat eye patients.
[2] ............................are used to connect computer net work.
[3] Light houses release a powerful........................................
[4] Cardboard, wood and metal are.....................................
[5] Different coloured bulbs are used for............................
Answers for activity 38
1- in straight lines 2- The combination of light rays
3- Thomes Alva Edison 4- endoscope
