Which metal pollute the air of a big city?
A). Copper
B). Chromium
C). Lead
D). Cadmium
2. Supersonic Jet causes pollution by thinning of
3. Spectacles used for viewing 3D films have
4. Which of the following is a natural dye ?
6. The Bhopal gas tragedy was caused by the gas
7. Which of the following substance is highly plastic ?
8. In a railway track two rails rejoined end to end with a gap in between them because