Across
- 4. prevents wastage of food
- 6. used to make diodes
- 7. a cheap and durable substitute for wood
- 9. backbone of industries
- 10. ____________ have superior properties than metals
- 11. CFC's eat away this layer
Down
- 1. used to kill unwanted herbs
- 2. study of materials
- 3. used to protect articles from corrosion
- 4. a drug used to fight against bacteria
- 5. metals are extracted from
- 8. man-made fibre