30. Why is wood an ideal material for building houses and furnitures? It is ______________. A. synthetic B. nonmetallic C. biodegradable D. rigid and tough

The ability of materials to conduct electricity.

What will happen to uncollected waste? A. It can produce waste. B. It can cause pollution. C. It can produce plastic. D. It can cause garbage.

(Harmful or Useful) old newspapers

(Harmful or useful) expired medicine

The ability of materials to be broken into pieces.

(harmful or Useful) fruit peelings

29. Why are water jugs made of plastics? A. Plastics are rust proof. B. Plastics are strong and absorbent. C. Plastics are shiny and water proof. D. Plastics are good conductors of heat.

What are the components of 5Rs techniques?

The ability of materials to be hammered into sheets.

26. Which explains why papers are used in writing? A. Papers are soft. B. Papers have the ability to dry up liquids like ink quickly. C. Papers are made of cellulose fibers that have absorbent property. D. Papers

What is the main reason for practicing the 5Rs? A. To solve or prevent environmental problems B. To worsen the environmental problems C. To throw the garbage everywhere D. To pile more trash in the landfill