7. It is caused by rapid growth and formation of abnormal cells into tumors. A. Cancer
B. diabetes
C. stroke
D. asthma

8. it caused by reduced flow of air to lungs.
A. Cancer
B. Heart attack
C. Allergy
D. Asthma

9. it caused by pollen, dust and other pollutants.
A. Stroke
B. Allergy
C. Heart attack
D. Asthma

10. Which of the following causes water pollution?
A. Burning garbage
B. Dumping garbage in rivers and seas
C. Oil spills in ocean
D. Both b and c

11. There are instances wherein fog combines with smoke from vehicles. What is this called?
A. Acid rain
B. Greenhouse effect
C. smog
D. fumes

12. How do we keep our water source clean?
A. Throw chemicals in the river
B. Wash clothes in the river
C. Throw dead animals in the sea
D. Do not pour harmful chemicals into drains and toilets

13. The following are wayd og keeping our air clean except one.
A. Using organic insecticide sprays
B. Avoid smoking
C. Bring your car for an emission
D. Burn tires to drive away mosquitoes

14. Motorcycle, ship and airport produce noise. Which among the causes of noise do these belong?
A. Construction site
B. entertainment
C. neighbor
D.transport

15. Allowed noise level by WHO in residential areas during night time is
A. 25 dB
B. 50 dB
C. 75 dB
D. 100 dB​